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Acta botánica mexicana

versión On-line ISSN 2448-7589versión impresa ISSN 0187-7151

Act. Bot. Mex  no.127 Pátzcuaro  2020  Epub 02-Jul-2020

https://doi.org/10.21829/abm127.2020.1687 

Research articles

Nomenclature survey of the genus Amaranthus (Amaranthaceae s.s.). 8. About Amaranthus polygonoides s.l. and A. anderssonii, two related taxa described from the tropical regions of America with notes on their taxonomy.

Estudio de nomenclatura del género Amaranthus (Amaranthaceae s.s.). 8. Sobre Amaranthus polygonoides s.l. y A. anderssonii, dos taxones relacionados descritos de las regiones tropicales de América con notas sobre su taxonomía.

1 University of Rome Sapienza, Department Department of Planning, Design, and Technology of Architecture, 00196 Rome, Italy.


Abstract

Background and Aims:

Amaranthus comprises 70-75 species of which about half are native to America. Some taxa are used as ornamentals, food or medicine and escape from cultivation, mainly causing economic impact to the agricultural systems. The genus is taxonomically critical due to its high phenotypic variability and hybridization that caused nomenclatural disorders. A note about Amaranthus polygonoides s.l. and A. anderssonii, whose nomenclature and taxonomy need to be still clarified, is presented.

Methods:

This work is based on examination of herbarium specimens and analysis of literature. Taxonomically relevant characters were measured (length and width (the widest part of the blade) of the leaves, longest and shortest diameters of the seeds, ratio length/width of the leaf blades and dehiscence/indehiscence of the fruits). The variability of the continuous characters was illustrated by box plots.

Key results:

The names Amaranthus polygonoides, A. anderssonii s.s., A. anderssonii f. erectus, A. taishanensis, Sarratia berlandieri, and Scleropus urceolatus are discussed. A specimen at BM-SL, that served as the base for the lectotype of A. polygonoides (Sloane’s illustration), was indicated. Previous holotype indications for Sarratia berlandieri and Scleropus urceolatus are corrected as lectotypes. Amaranthus taishanensis is confirmed to be a synonym of A. polygonoides s.s. The morphological study of leaves and seeds, as well as data about the distribution and the available phylogenetic analyses, show that the taxa can be distinguished at infraspecific ranks. A new classification is proposed recognizing a single species (A. polygonoides) with two subspecies, subsp. urceolatus comb. nov. and subsp. polygonoides. The latter taxon includes var. berlandieri comb. nov. and var. polygonoides.

Conclusions:

Amaranthus polygonoides s.l. and A. anderssonii are native to tropical regions of America, currently treated as separate taxa. The use of box plots, along with the available phylogenetic analyses, helped to clarify their taxonomy.

Key words: Amaranthus berlandieri; A. taishanensis; A. urceolatus; distribution; Amaranthus subg. Albersia; typification

Resumen

Antecedentes y Objetivos:

Amaranthus comprende 70-75 especies, de las cuales cerca de la mitad son nativas de América. Algunas especies son usadas como ornamentales, alimento o medicina y escapan de cultivo causando daños económicos a los sistemas agriculturales. El género tiene interés crítico debido a su alta variabilidad fenotípica e hibridación, lo que ha generado desorden nomenclatural. Se presenta una nota sobre Amaranthus polygonoides y A. andressonii, cuya nomenclatura y taxonomía todavía necesita ser clarificada.

Métodos:

Este trabajo está basado en la revisión de especímenes de herbario y el análisis de la literatura. Se midieron caracteres taxonómicamente relevantes (longitud y ancho (parte más ancha de la lámina) de las hojas, relación largo/ancho de las hojas, tamaño de la hoja, diámetro más largo y más corto de las semillas y dehiscencia/indehiscencia de los frutos). La variabilidad de los caracteres continuos se ilustró con diagramas de caja.

Resultado clave:

Los nombres Amaranthus polygonoides, A. anderssonii s.s., A. anderssonii f. erectus, A. taishanensis, Sarratia berlandieri y Scleropus urceolatus son discutidos. Se indicó un espécimen en BM-SL que sirvió de base para el lectotipo de A. polygonoides (Ilustración de Sloane). Reportes previos de holotipos para Sarratia berlandieri y Scleropus urceolatus son corregidos como lectotipos. Amaranthus taishanensis se confirma como un sinónimo de A. polygonoides subsp. polygonoides. El estudio morfológico de las hojas y semillas, así como datos sobre la distribución y los análisis filogenéticos disponibles, muestran que los taxa pueden ser distinguidos en rangos infraespecíficos. Se propone una clasificación nueva, reconociendo una sola especie, A. polygonoides, con dos subespecies, subsp. urceolatus comb. nov. y subsp. polygonoides. Este último taxón incluye var. berlandieri comb. nov. y var. polygonoides.

Conclusiones:

Amaranthus polygonoides s.l. y A. anderssonii son nativos de las regiones tropicales de América y actualmente se consideran como taxones separados. El uso de diagramas de caja, junto con los análisis filogenéticos disponibles, ayudó a aclarar su taxonomía.

Palabras clave: A. berlandieri; A. taishanensis; A. urceolatus; distribución; Amaranthus subg. Albersia; tipificación

Introduction

Amaranthus L. (Amaranthaceae s.s.) is a genus comprising 70-75 species with worldwide distribution. Approximately half of these species are native to America, whereas the remaining ones occurs in the other continents. Various taxa are used as ornamentals, food, and medicine. Some species can escape from cultivation, mainly causing economic impact to agricultural systems with reduction in productivity and crop quality (see e.g., Costea et al., 2001; Hernández-Ledesma et al., 2015; Iamonico, 2015a; Das, 2016).

Amaranthus is critical from the taxonomical point of view due to its high phenotipic variability and hybridization that caused nomenclatural disorders and name misapplications (see e.g., Mosyakin and Robertson, 1996; Costea et al., 2001; Iamonico, 2015a, b, 2016b, 2017, 2020; Iamonico and Galasso, 2018).

Amaranthus polygonoides L., and A. anderssonii J.T. Howell are two taxa described from the tropical regions of America (Galápagos archipelago, the Caribbean, Mexico, and Texas (central and southern USA)) (see e.g., Bayón, 2015), which belong to Amaranthus subgen. Albersia (Kunth) Gren. & Godr. sensuMosyakin and Robertson (1996). According to phylogenetic analyses based on molecular studies (see e.g., Waselkov, 2013; Waselkov et al., 2018) and morphological data (see e.g., Bayón, 2015), these two species are highly variable and closely related. Some nomenclatural issues about these taxa, as well as taxonomic problems, need to be clarified and are dealt with in the present paper. In addition, the following names were considered and discussed: Amaranthus taishanensis F.Z. Li & C.K. Ni, Sarratia berlandieri Moq. (≡ A. berlandieri (Moq.) Uline & W.L. Bray), Scleropus urceolatus Ands. (≡ A. anderssonii J.T. Howell).

This work is part of the ongoing nomenclatural studies of all Amaranthus names, representing the eighth contribution (the first seven papers were on the Linnaean names (Iamonico, 2014a, b), the names linked to the Italian flora (Iamonico, 2016a), Amaranthus gracilis Desf. and related names (Iamonico, 2016b), Moquin-Tandon’s names published in Candolle’s Prodromus (Iamonico, 2016c), the names linked to the Australian flora (Iamonico and Palmer, 2020), and Willdenow’s names (Iamonico, 2020).

Material and Methods

This work is based on examination of specimens deposited at BM, CAS, E, FI, G, GH, IBSC, L, LG, LINN, MA, NAP, NAS, NY, P, PE, PAD, QCA, RO, and US (acronyms according to Thiers, 2020+), and analysis of relevant literature (protologues, taxonomic treatments, morphological, and molecular investigations).

The following characters, which are relevant for the studied taxa according to literature (mainly Henrickson, 1999) and personal experience, were measured on the examined specimens (see “Additional examined material”) using a millimeter ruler and an optical microscope (Carl Zeiss, Göttingen, Germany): length and width of the leaves (the width was measured at the widest part of the blade), size of the seeds (both longest and shortest diameter), ratio length/width of the leaf blades, and fruit dehiscence/indehiscence. The variability of the continuous characters (leaves and seeds) was illustrated by box plots.

The articles cited through the text follow the Shenzen Code, hereafter abbreviated as ICN (Turland et al., 2018).

Results and Discussion

Nomenclature

Amaranthus polygonoides

Linnaeus (1759: 27) validly published the name Amaranthus polygonoides through a short diagnosis (“Calycibus infundibuliformis obtusis singularis”) and the following citation: “Sloan. Jam. I. t. 92. f. 2”. This latter quotation refers to Sloane’s work (1707) about his Voyage to the Islands Madera, Barbados, Nieves, S. Christophers and Jamaica. Kellogg (1988: 160) indicated a specimen preserved at BM in Sloane’s collection (BM-SL no. 2-116) as the type of A. polygonoides. However, this specimen was never seen by Linnaeaus (see Jarvis, 2007: 157-159). The lectotype of the Linnaean name was correctly proposed by Henrickson (1999: 797) based on Sloane’s image “t. 92. f. 2”. Note that the BM specimen was the base for Sloane’s image, so it can be considered as a typotype (see Jarvis, 2007: 22-24) (the illustration is the mirror image of the specimen). The BM specimen is here indicated as the typotype for the first time.

Amaranthus taishanensis

Li and Ni (1981: 116) validly published Amaranthus taishanensis from Eastern China (Province of Shandong) on the basis of Li’s collections in the cities of Taian (locus classicus) and Jinan. The authors morphologically compared the new proposed species with A. angustifolius Lam. (currently accepted as A. graecizans L. s.s.; see Iamonico, 2015a) by the synflorescence structure, the number of the tepals in the pistillate flowers, the number of the stamens, and the length of the fruit. Twenty one years later, Li et al. (2002) clarified the identity of A. taishanensis, stating that this name is a heterotypic synonym of A. polygonoides. I examined an isotype of A. taishanensis at PE and can confirm this synonymy based on the current concept in Amaranthus (see e.g., Mosyakin and Robertson, 2003; Bayón, 2015; Iamonico, 2015a).

Sarratia berlandieri sensu stricto

The name Sarratia berlandieri was validly published by Moquin-Tandon (1849: 268-269) who provided a short diagnosis, a detailed description, and the provenance (“In Mexico inter S. Fernando ae Matamoros”); a specimen (“Berland.! N. 2279”) was also cited.

Bayón (2015: 348) indicated the “holotipo” of this name, a specimen preserved at G (code 00236968), and four “isotipos” at G (barcodes G00236969, and G00236970), GH (barcode GH00036984), and NY (barcode NY991138). Note that Bayón (l.c.), as “no visto” (= not seen) for all these five specimens. Because Moquin-Tandon (1849: 268-269) did not cite any holotype, the term “holotipo” as reported by Bayón (l.c.) is an error to be corrected to lectotype according to the Art. 9.10 of the ICN, whereas isolectotypes must replace Bayón’s “isotipos” for the other cited four specimens. Note that only the G00236969, G00236970, and GH00036984 exsiccata bear original annotations with the date of collection (year “1830”), whereas NY991138 lacks this information. However, because J.-L. Berlandier (a Belgian explorer in North America and Mexico, and traveller of A. P. de Candolle) died in 1851 (just two years later than the publication of the Moquin-Tandon’s treatment of Amaranthaceae in Candolle’s Prodromus (year 1849)) (see Stafleu and Cowan 1976: 196), it is reasonable that the NY undated specimen was also collected before 1849 and seen by Moquin-Tandon (1849). Few months later than Bayón (l.c.), Iamonico (2016c: 109) again proposed to lectotypify the name Sarratia berlandieri on the specimen G00236970 (reported by Iamonico (l.c.) under the SIB identifier 189573/3 according to the G (CHG, 2020c)), also highlighting the occurrence of other three sintypes (G00236968, G00236969 (reported by Iamonico (l.c.) under the SIB identifiers 189573/1, 189573/2 according to the G online Herbarium database), and PH00022348). Although the lectotypification by Iamonico (l.c.) was formally correct, it was superseded by that proposed (and here corrected) by Bayón (l.c.) (see Art. 9.19 of ICN). Note that the PH specimen cited by Iamonico (l.c.), and not reported by Bayón (l.c.), was not formally designated as isolectotype; therefore, this designation is made here (see “Taxonomic Treatment”). In addition, I traced further two specimens at P (barcodes P00609930, and P00609931; images available at MNHN, 2019) originally numbered as “2279” (as reported in the protologue by Moquin-Tandon (1849: 268-269)) but collected in different years than 1830 (the date of sintypes), i.e. 1832 and 1846. As a consequence, these two P specimens cannot be considered for lectotypification purposes.

Scleropus urceolatus by Andersson and Amaranthus anderssonii s.l.

Howell (1933: 95) proposed Amaranthus anderssonii as nomen novum pro Scleropus urceolatus Ands. (year 1853) based on the previously and validly published A. urceolatus Benth. (year 1844). According to Art. 7.4 of the ICN, the type of A. anderssonii is that of S. urceolatus. Andersson (1853: 162-163) provided a diagnosis and a detailed description also indicating the provenance (“Hab. locis graminosis regionis inferioris insulae Indefatigable (Ipse)”). Bayón (2015: 305) indicated the “holotipo” for this name, a specimen preserved at S (S5637), as “no visto” (= not seen). Because Andersson (1853: 162-163) did not cite any holotype, the term “holotipo”, as reported by Bayón (l.c.), is an error to be corrected to lectotype according to the Art. 9.10 of the ICN.

Howell (1933: 96) also validly described a new form of Amaranthus anderssonii, named f. erectus. The new taxon would be distinguished from the nominal one (f. anderssonii) by its habit (erect vs. spreading), length and shape of the perianth (2-2.5 mm, “tubular” vs. about 2 mm, “strongly urceolate”). Bayón (2015: 305) indicated the “holotipo” of this name, a specimen preserved at CAS (barcode CAS203293), as “no visto” (= not seen). Because Howell (1933: 96) reported a specific exsiccatum by the indication of the collection number (9837), the herbarium specimen (CAS) with the barcode (203293) and no duplicates were traced in other herbaria, I agree with Bayón (l.c.) that CAS203293 is the holotype of the name Amaranthus anderssonii f. erectus (see also the considerations by McNeill (2014) about the holotype citations).

Historical background

The taxa here considered were discussed and differently treated through time by various authors.

Moquin-Tandon (1849: 268-270) treated the taxa polygonoides and berlandieri as part of two different genera, i.e. Sarratia Moq. (a new proposed genus in Candolle’s Prodromus, with the new species S. berlandieri Moq.) and Amblogyna Raf. (including the species A. polygonoides (L.) Raf.). On the basis of Moquin-Tandon’s treatment, these two genera would differ from each other by the number of the tepals in the pistillate flowers (5 (Sarratia) vs. 3 Amblogyna)), the number of the stamens (5 vs. 3), lobes of the tepals (unequal vs. equal), the number of the stigmas (3-4 vs. 2-3), and the fruit (indehiscent vs. dehiscent).

Uline and Bray (1894: 268-270) accepted Amaranthus berlandieri and A. polygonoides as separated species. They placed A. berlandieri in the group of monoecious species with 2-3 stamens and indehiscent fruits (together with A. urceolatus Benth.), whereas A. polygonoides was included in the group with dehiscent fruits (together with A. fimbriatus Benth., A. pringlei S.Watson, and A. squarrulosum (A. Gray) Uline & W.L. Bray). Amaranthus anderssonii was not mentioned by Uline and Bray (l.c.).

Thellung (1914: 350-354) recognized Amaranthus polygonoides and A. berlandieri as separated taxa, proposing the subspecies rank for the taxon berlandieri (a new proposed combination in the Synopsis der Mitteleuropäischen Flora). Amaranthus anderssonii was not mentioned.

Standley (1917: 102, 104-105), in his treatment of Amaranthus for the North American Flora, distinguished Amaranthus polygonoides from A. berlandieri by the fruit (dehiscent vs. indehiscent, respectively) and the number and shape of the leaves (“suborbicular to obovate to oval...not crowed” vs. “oblong-lanceolate... crowed at the end of the branches”, respectively). Amaranthus anderssonii was not mentioned.

Eliasson (1985: 416-418) observed that Amaranthus anderssonii is similar to A. berlandieri sharing both vegetative and sexual characters (stem pubescence, synflorescence structure, shape and structure of the tepals, number of stamens, seed ratio length/width, and ornamentation), but differ from each other by the habit and distribution. Amaranthus polygonoides was not mentioned by Eliasson (l.c.).

Henrickson (1999: 794-799) widely discussed the names Amaranthus polygonoides and A. berlandieri, observing that the dehiscence/indehiscence of the fruits is not a constant character and stating “Specimens attributable to Amaranthus berlandieri are mostly indehiscent... but a few specimens did not show a distinct encircling line below the rugate cap of the utricle. In the 76 collections of A. polygonoides with mature fruit examined, 36 were noted to be actually circumscissile... and 35... were clearly indehiscent”. Concerning the leaves, Henrickson (1999: 796-797) highlighted a partial overlapped range of the ratio length/width of the blades, but no geographic separation occurs between the two taxa. He, therefore, concluded that the “Recognition of two taxa... would be quite arbitrary”.

Bojian et al. (2003) just mentioned Amaranthus polygonoides in a note under A. taishanensis, which was considered different from the Caribbean taxon and it would be more related to A. blitum L. (“one of us (Clemants) notes that further study might ally A. taishanensis with A. blitum, from which it seems to differ only by having five sepals”).

Mosyakin and Robertson (2003) reported Amaranthus berlandieri as synonym of A. polygonoides, following Henrickson (1999). However, they stated that “The subspecies rank may be more appropriate for A. berlandieri, as was suggested by Thellung (1914). The relationships between these taxa of the A. polygoniodes aggregate require additional study”.

In my recent paper on the Moquin-Tandon’s name in Amaranthus (Iamonico, 2016c), I provisionally accepted the Henrickson’s (1999) scheme, but I stated that “further studies are necessary to be carried out”.

Taxonomic remarks

Morphology

The results obtained in the present study confirm that dehiscence/indehiscence of the fruit cannot be considered as a constant character, as already highlighted by Henrickson (1999). On the contrary, the box plots show a separation of the studied taxa based on leaf blade and seed sizes.

Concerning the size of the leaf blades, a difference in the ratio length/witdh occurs among Amaranthus anderssonii, A. berlandieri, and A. polygonoides. The lower ratio charaterizes A. anderssonii (range 1.25-1.67), followed by A. polygonoides which ratio value (1.30-2.60) partially overlaps with those of A. berlandieri (2.60-4.20) (Fig. 1). Between A. polygonoides and A. berlandieri there is also a difference in the shape of the leaves which is, respectively, ovate to obovate and lanceolate.

Figure 1 Box plots for the ratio leaf length/leaf width. Medians (horizonthal bar), 25th and 75th percentiles, and maximum and minimum (wiskers) of selected features are shown. ande = Amaranthus anderssonii J.T. Howell; berl = A. berlandieri (Moq.) Uline & W.L. Bray; poly = A. polygonoides L. 

Amaranthus anderssonii displays smaller seeds, having the longest diameter as 0.69-0.83 mm long and the shortest diameter ranging from 0.50-0.63 mm (Fig. 2A-B). On the other hand, A. berlandieri and A. polygonoides are more similar to each other, because the 25th and 75th percentiles of the longest diameter of the seed slightly overlap between them (total ranges are 0.81-0.87 mm for A. berlandieri vs. 0.80-1.00 mm for A. polygonoides); the variability of the shortest seed diameter of A. polygonoides is almost completely included in that of A. berlandieri (vs. 0.63-0.71 mm for A. berlandieri, and 0.68-0.71 mm for A. polygonoides). Note, however, that A. berlandieri shows narrower seeds (Fig. 2B).

Figure 2 Box plots for the seeds: A. seed lenght (measurements in mm); B. seed width (measurements in mm). Medians (horizonthal bar), 25th and 75th percentiles, and maximum and minimum (wiskers) of selected features are shown. ande = Amaranthus anderssonii J.T. Howell; berl = A. berlandieri (Moq.) Uline & W.L. Bray; poly = A. polygonoides L. 

Phylogenetic analysis of molecular data

According to the recent molecular phylogenetic study by Waselkov et al. (2018), the only one among the published molecular papers on Amaranthus that includes Amaranthus anderssonii (A. berlandieri was considered as synonym of A. polygonoides), it was clearly shown that A. polygonoides (a Caribbean species) is the most closely related taxon to the endemic A. anderssonii (from Galapágos). In fact, these two species form a strongly supported clade (informally named “Anderssonii clade”; bootstrap values = 100 (nuclear markers), and 98 (chloroplast regions); see Waselkov et al., 2018: 446, Fig. 1 A-B). Both A. anderssonii and A. polygonoides are part, in turn, of the unresolved “Galapágos clade” as informally named by Waselkov et al. (2018). The phylogenetic tree based on nuclear markers (Waselkov et al., 2018: 446, Fig. 1A) shows that the species related to the “Anderssonii clade” were A. tamaulipensis Henrickson (the earliest divergent lineage in the clade formed by tamaulipensis+anderssonii+polygonoides, with a bootstrap value = 95), and A. crassipes (three accessions forming a strongly supported clade (bootstrap values = 100)). On the other hand, the tree derived from the analysis of the chloroplast regions (Waselkov et al., 2018: 446, Fig. 1B), places A. tamaulipensis as separated species, but related to both Anderssonii and crassipes clades.

The nuclear markers tree (Waselkov et al., 2018: 446, Fig. 1A) shows the “Anderssonii clade” + A. tamaulipensis and the crassipes-clade forming a moderately supported clade (bootstrap value = 88). The whole group (tamaulipensis+anderssonii+polygonoides+crassipes) is sister group to the large clade (bootstrap values = 84-100) informally named “ESA + South American” (ESA = Eurasian/South Africa/Australian; see Waselkov et al., 2018: 447, caption of Fig. 1). Note that the other taxa belonging to the “Galápagos Clade” sensuWaselkov et al. (2018: 446) form a well-supported clade that is not closely related to the tamaulipensis+anderssonii+polygonoides+crassipes group. The tree derived from the chloroplast regions shows the Anderssonii+crassipes+tamaulipensis clade with low support; however, relationships among major clades within Amaranthus are not resolved and/or have moderate to low support values. Simplified phylogenetic relationships within Amaranthus based on Waselkov et al. (2018) are shown in Fig. 3.

Figure 3 Phylogenetic relationships within Amaranthus L., based and simplified from Waselkov et al. (2018): A. nuclear markers (ITS, A36, G3PDH, and Waxy), B. chloroplast regions (trnL5′-trnL3′ and matK/trnK). Triangle size is proportional to sample size. Legend: ••• = high support (bootstrap values: 100-95), •• = medium support (bootstrap values: 94-75), • = low support (bootstrap values: 7-50), -- = no bootstrap value provided by Waselkov et al. (2018)

Taxonomic conclusion

The three taxa here studied are currently recognized as two separated species, A. anderssonii and A. polygonoides (see e.g., Bayón, 2015: 305, and 348, respectively). The taxon berlandieri is synonymized with the latter name, although various authors (e.g., Mosyakin and Robertson, 2003; Iamonico, 2016c) highligthed that additional studies are required to clarify the correct relationship between these taxa.

The results obtained in the present study showed that the taxa anderssonii, berlandieri, and polygonoides can be distinguished based on some morphological characters (i.e., leaf blade shape and length/width ratio, as well as seed size). The ranges of these characters just partially overlap among the taxa, especially between berlandieri and polygonoides. Molecular phylogenetic analyses by Waselkov et al. (2018) revealed a relationship between A. anderssonii and A. polygonoides. Moreover, there is a geographic separation: the taxon anderssonii is endemic to Galápagos archipelago, the taxon polygonoides occurs in the Caribbean and coastal areas of Texas, and the taxon berlandieri occurs in Mexico and inland areas of Texas.

Based on the current definition of infraspecific ranks, subspecies, varieties, and forms, those taxa can be treated as groups that are distinguishable based on morphology (despite having overlapping ranges), with a geographical, ecological and/or reproductive isolation (see e.g., Hardion et al., 2017). The group anderssonii-berlandieri-polygonoides represents a case that can be treated as a single species with different infraspecific taxa. Because there is high morphological similarity among them, and considering the adjacent distribution areas between berlandieri and polygonoides as compared to anderssonii, I here propose to treat the latter taxon at subspecies rank of A. polygonoides (the earliest published name at species level), whereas the taxon berlandieri will be recognized at variety level (new nomenclatural change, see below) of the subsp. poligonoides (automatically estabilished according to Art. 26.3 of the ICN). Note that there is an earlier basionym for A. anderssonii (Scleropus urceolatus), so it must be used as the base of my proposed combination (see below).

Amaranthus polygonoides L. subsp. urceolatus (Ands.) Iamonico, comb. et stat. nov.

Scleropus urceolatus Ands., Kong. Svenska Vetensk. Acad. Handl., n.s. 3(41): 162-163. 1853.

Amaranthus anderssoniiJ.T.Howell, Proc. Calif. Acad. Sci., ser. 4 21: 95. 1933 (Fig. 4). TYPE: ECUADOR. Galápagos, Galapágos-öarna, Indefatigable (Isla Santa Cruz), X.1852, N. J. Andersson and J. Nils s.n. (S-R5637!, lectotype designated by Bayón, 2015: 305 (as “holotipo”, here corrected according to the Art. 9.10; image of the lectotype available at JSTOR, 2019a).

Figure 4 Specimen of Amaranthus polygonoides subsp. urceolatus (Ands.) Iamonico (Galápagos, Island Española, J. T. Howell 8703, CAS368651). 

= Amaranthus anderssoniiJ.T. Howell f. erectus J.T. Howell, Proc. Calif. Acad. Sci., ser. 4, 21: 96. 1933. TYPE: ECUADOR. Galápagos, Isla Duncan, 7.V.1832, J. T. Howell 9837 (holotype: CAS203293!; image of the holotype available at CAS Botany Collection Database (CAS, 2020)).

Distribution: endemic from Galápagos archipelago (Islands Baltra, Española, Santa Cruz, and Santiago; Eliasson, 1985: 432; Bayón, 2015: 305). Not known elsewhere.

Amaranthus polygonoides L., Pl. Jamaic. Pug.: 27. 1759 subsp. polygonoides var. polygonoides

Roemeria polygonoides (L.) Moench, Methodus (Moench): 341. 1794.

Amblogyna polygonoides (L.) Raf., Fl. Tellur. 3: 42. 1837.

Albersia polygonoides (L.) Kunth, Fl. Berol. ed.2, 2: 144. 1838.

Amblogyna polygonoides Danzell & A. Gibson., Bombay Fl.: 219. 1861, nom. illeg. (Art. 53.1 of ICN) (Fig. 5). TYPE: (icon) t. 92, f. 2 “Blitum polygonoides viride seu ex viridi et albo variegatum polyanthos” in Sloane (1707: 144) (lectotype designated by Hendrickson (1999: 797); image of the lectotype available at BHL, 2020); typotype (here indicated) BM-SL no. 2: 166 (NHM, 2020).

= Amaranthus taishanensisF.Z. Li & C.K. Ni, Acta Phytotax. Sin. 19(1): 116. 1981. TYPE: CHINA. Shandong, Taian, 26.VI.1979, F. Z. Li 00116 (holotype: SDFS non vidi fideLi et al. (2002: 384); isotypes: PE00024069! (CVH, 2004-2015), and SDNU non vidi fide Li and Ni (1981: 116, reported as “herbarium of Forestry School of Shantung Province”), and Li et al. (2002: 384)).

= Amaranthus verticillatus Pav. in Moquin-Tandon (1849: 268, 270), nom. inval. pro syn. of Amblogina polygonoides (≡ Amaranthus polygonoides) (Art. 36.1b of ICN).

Figure 5 Specimen of Amaranthus polygonoides L. subsp. polygonoides var. polygonoides (Antigua, St. John’s, J. A. Shafer 35, NY1373866). 

Distribution: native to the Caribbean and the coastal areas of Texas (Eliasson, 1985: 432). Out of the native range Amaranthus polygonoides s.l. was recorded in Europe as a casual alien species (Iamonico, 2011), in Africa as naturalized in Egypt (Iamonico, 2015b), and in Asia (China; Bojian et al., 2003 under A. taishanensis).

Amaranthus polygonoides L. subsp. polygonoides var. berlandieri (Moq.) Iamonico, comb. et stat. nov.

Sarratia berlandieri Moq., Prodr. (DC.) 13(1): 268-269. 1849.

Amaranthus berlandieri (Moq.) Uline & W.L. Bray, Bot. Gaz. 19: 268. 1894.

Amaranthus polygonoides L. subsp. berlandieri (Moq.) Thell., Syn. Mitteleur. Fl. 5(1): 352. 1919 (Fig. 6). TYPE: MEXICO. Tamulipas, Ranchos del Mojete de Matamoros à San Fernando, X.1830, J.-L. Berlandier 2279 (G00236968!, lectotype designated by Bayón, 2015: 348 (as “holotipo”, here corrected according to the Art. 9.10; image of the lectotype available at CHG, 2020a); isolectotypes at G00236969 (CHG, 2020b), G00236970 (CHG, 2020c), GH00036984 (CHG, 2020d), NY991138 (NYBG, 2020) (designated by Bayón, 2015: 348 (as ”isotipos”, here corrected according to the Art. 9.10), and PH00022348 (here designated; JSTOR, 2019b).

Figure 6 Specimen of Amaranthus polygonoides subsp. polygonoides var. berlandieri (Moq.) Iamonico (USA, Texas, Cameron, W. R. Carr 29880, NY3042458). 

Distribution: native to Mexico and inland areas of Texas (Eliasson, 1985: 432).

A diagnostic key for the infraspecific taxa of Amaranthus polygonoides, as recognized in the present paper, is shown here. The distribution areas are also reported.

  • 1a. Ratio length/width of the leaf blades 1.30-4.20; seeds with longest diameter 0.80-1.00 mm long, and shortest diameter 0.63-0.71 mm long ..................................................................................... subsp. polygonoides

  • 2a. Ratio length/width of the leaf blades (1.30-)1.60-2.10(-2.60), blades ovate to obovate; seeds with longest diameter 0.80-1.00 mm long, and shortest diameter 0.68-0.71 mm long; Caribbean and coastal areas of Texas ................................................ var. polygonoides

  • 2b. Ratio length/width of the leaf blades (2.60-)2.90-3.90(-4.20), blades lanceolate; seeds with longest diameter 0.81-0.87 mm long, and shortest diameter 0.63-0.71 mm long; Mexico and inland areas of Texas .................................. var. berlandieri (Moq.) Iamonico

  • 1b. Ratio length/width of the leaf blades (1.25-)1.30-1.60(-1.67); seeds with longest diameter 0.69-0.83 mm long, and shortest diameter 0.50-0.63 mm long; Galápagos Islands ................. subsp. urceolatus (Ands.) Iamonico

Additional examined material: Amaranthus polygonoides subsp. polygonoides var. berlandieri. MEXICO. De S. Fernando à Matamoros, 1832, J.-L. Berlandier 2279 (P00609930); 1846, J.-L. Berlandier 2279 (P00609931). UNITED STATES OF AMERICA. Texas, Travis, 20.V.1872, E. Hall 534 (NY3364372); Nueces, 23-30.III.1894, A. A. Heller 1487 (NY3364377); Duval, 1888, M. B. Croft 223 (NY3364371); Austin, 15.VII.1936, B. C. Tharp s.n. (GH01929204); Starr, 1 mile E. of Davis Oil Fileld Cafe, 11.XII.1940, V. L. Cory 36134 (GH01929193); Hidalgo, Rio Grand Valley, 02.VIII.1942, M. L. Walker 32 (NY3364367); Aransas Refuge, 10.I.1944, V. L. Cory 45967 (GH01929197); Cameron, on waste grounds in The Lower Rio Grande Valley at Brownsville, 02.X.1965, R. Runyon 5936 (GH01929194); Cameron, agricultural landscape on delta of Rio Grande, 20-25 ft., 19.VII.2011, W. R. Carr 29880 (NY3042458).

Amaranthus polygonoides subsp. polygonoides var. polygonoides. ANTIGUA AND BARBUDA. Antigua, near St. John’s, I.1907, J. A. Shafer 35 (NY1373866); Antigua, Gunthorpes, 06.X.1937, H. E. Box 1140 (US01084457). BAHAMAS. Great Inagua, Mathew town, 15.X.1904, G. V. Nash 1079 (NY1373847). BELGIUM. Wallonia, Béthane (Goé), Adv. Laineir dans la cour du lavoir, 16.IX.1959, N. Cnops s.n. (sub. A. vulgatissimus Spegaz.), rev. J. Duvigneaud and J. Lambinon (LG). CHINA. Su Xian, 1983, Xuewen Wang (王学文) 1604 (IBSC0190235); Xiyan Yanzhou, Shandong, in fields, 50 m, 28.VI.2004, C. Yong Guo 15030101 (P00871046); ibidem (MA896135); Shimenshan, Qufu, Shandong, near water, 300 m, 06.VII.2004, Cheng Yong Guo 1501116 (P00871059); Jiangsu, Xuzhou, 18.VIII.2011, L. Qixin, Xiong Yuning (刘启新,熊豫宁) 10-1-117 (NAS00591444, NAS00591445); Jiangsu, Xuzhou, 01.VII.2013, L. Qixin, Xiong Yuning (刘启新,熊豫宁) 3291 (NAS005914429, NAS00591446). CUBA. La Habana, La Universidad, 09.XI.1921, E. L. Eckman 13470 (NY1373862). CURAÇAO. Mt. Pleasant, 20-27.III.1913, N. L. Britton and J. A. Shafer 3123 (US01099924). DOMINICAN REPUBLIC. Hispaniola, Santiago de los Caballeros, 17.IV.1954, J. J. Jiménez Almonte 2653 (US00847576); Pedernales, Aguas Negras, 24-27.VI.1975, A. H. Liogier 23282 (NY1373850); La Altagracia, in town of Boca de Yuna, at W side of Rio Duey (Rio Yuma) at Mar Caribe, 8 m, 24.II.1981, T. A. Zanoni 10603 (NY13738653); La Altagracia, Isla Sona, 29.VI.1981, T. A. Zanoni 15162 (NY1373857). GUADALOUPE. Terrain sablonneux de la Desirade, 1893, A. Duss 2793 (NY1373852). HAITI. L’Artibonite, Southeast of Gros Morne, Vicinity of Gros Morne, Départment de l’Artibonite, 235 m, 1926, E. C. Leonard 9973 (NY1373861). ITALY. Abruzzo, Giulia, sine die (ante 1831), M. Tenore s.n. (NAP); Campania, Golfo di Napoli, sine die (ante 1817), G. Gussone s.n. (NAP-GUSS); Puglia, Barletta, 1822, A. Bruni s.n. (G00189974); Marche, Ascoli, sine die (century XIX), sine collectore s.n., det. G. Lusina (RO); Marche, Porto d’Ascoli, VII.1839, P. Sanguinetti s.n., det. G. Lusina (RO); Marche, Senigallia, sui binari della stazione ferroviaria, 30.VI.1946, A. Bettini s.n. (FI(3)); Marche, da semi di piante di Senigallia sul mio terrazzo in vaso, 22.VII.1949, A. Bettini s.n. (FI); Lombardia, nasce nell’Orto botanico di Mantova spontaneo, sine die (XIX century), sine collectore s.n. (PAD); Lombardia, nelle sabbie e negli incolti nel mantovano, III.1877, Barbieri s.n. (FI); Toscana, Giardino dei Semplici, 1820, sine collectore s.n. (FI); Toscana, Hort. Bot. Bonon, 1829, P. Bubani s.n. (FI); Toscana, H Pisano, 1839 ect., sine collectore s.n. (FI); Toscana, H. Bot. Mus. Flor., 27.VI.1857, sine collectore s.n. (FI); Veneto, Orto Botanico di Padova, coltivato, VIII.1896, Adr. Fiori s.n. (FI). THE NETHERLANDS. Brabant, Tilburg, 19.IX.1955, J. H. Kern et al. 0823314 (L), 0823316 (L), 0823317 (L); Brabant, Tilburg, 01.IX.1958, J. H. Kern, S. J. van Ooststroom and T. V. Reichgelt 0823315 (L); Brabant, Stortterrein afval Tilburg e Wolwasserij, 13.IX.1962, J. Dorgelo 0823313, det. F. Adema (L); Sine loc., 1964, P. Aellen 00295340 (E). UNITED STATES OF AMERICA. Florida, Key West, II.1846, F. Rugel 31 (GH01929190); Texas, 7.5 miles SSW of Woodsboro... in disturbed clay at the gate to the lake Trap, river Pasture, 24.IX.1978, S. R. Hill 7905 (NY3364376).

Amaranthus polygonoides subsp. urceolatus (≡ A. anderssonii). ECUADOR. Galápagos, Isla Española, Punta Suarez, 3 m, V.1975, H. H. Werff 2055 (QCA4061!); Galápagos, Galapágos - öarna, Indefatigable (Santa Cruz Island), 1853, N. J. Andersson s.n. (S07-12528!); Galápagos, Island Española, Gardner Bay, 20.IV.1932, J. T. Howell s.n. (CAS368651!); Galápagos, Santiago Island, James Bay, James Island, 05.VI.1932, J. T. Howell s.n. (CAS368652!); Galápagos, Santiago Island, Sullivan Bay, James Island, 13.VI.1932, J. T. Howell 10053 (CAS368653!); Galápagos, Isla Española, Punta Suarez, 10 ft, V.1975, van der Werff 2055 (CAS368656!).

Acknowledgements

Thanks to the Directors and Curators of the herbaria cited. I am also greatful to L. García-Morales (Tecnológico de Ciudad Victoria, Mexico) for his help with the Spanish translation of the Abstract.

Literature cited

Andersson, N. J. 1835. Om Galapágos-öarnes Vegetation. Kongliga Svenska vetenskaps-akademiens handlingar, n.s. 3(41): 61-256. [ Links ]

Bayón, N. D. 2015. Revisión taxonómica de las especies monoicas de Amaranthus (Amaranthaceae): Amaranthus subg. Amaranthus y Amaranthus subg. Albersia. Annals of the Missouri Botanical Garden 101(2): 261-383. [ Links ]

BHL. 2020. Biodiversity Heritage Library. A voyage to the Islands Madera, Barbados, Nieves, S. Christophers and Jamaica, with the Natural History of the Herbs and Trees, Four-footed Beasts, Fishes, Birds, Insects, Reptiles, and C. of the last of those Islands, Vol. 1. https://www.biodiversitylibrary.org/item/11242#page/528/mode/1up (consulted January, 2019). [ Links ]

Bojian, B., S. E. Clemants and T. Borsch. 2003. Amaranthus L. In: Wu, Z. Y., P. H. Raven and D. Y. Hong (eds.). Flora of China 5. Science Press and Missouri Botanical Garden Press. Beijing, China and St. Louis, USA. Pp. 415-429. [ Links ]

CAS. 2020. Botany Collection Database Amaranthus anderssonii J.T. Howell f. erectus J.T. Howell. http://researcharchive.calacademy.org/image_db/botany/cas0000461.jpg (consulted January, 2019). [ Links ]

CHG. 2020a. Catalogue des Herbiers de Genève (CHG). Conservatoire and Jardin botanique de la Ville de Genève. Sarratia berlandieri Moq. http://www.ville-ge.ch/musinfo/bd/cjb/chg/adetail.php?id=187129&base=img&lang=en (consulted January, 2019). [ Links ]

CHG. 2020b. Catalogue des Herbiers de Genève (CHG). Conservatoire and Jardin botanique de la Ville de Genève. Sarratia berlandieri Moq. http://www.ville-ge.ch/musinfo/bd/cjb/chg/adetail.php?id=187130&base=img&lang=en (consulted January, 2019). [ Links ]

CHG. 2020c. Catalogue des Herbiers de Genève (CHG). Conservatoire and Jardin botanique de la Ville de Genève. Sarratia berlandieri Moq. http://www.ville-ge.ch/musinfo/bd/cjb/chg/adetail.php?id=187131&base=img&lang=en (consulted January, 2019). [ Links ]

CHG. 2020d. Catalogue des Herbiers de Genève (CHG). Conservatoire and Jardin botanique de la Ville de Genève. Sarratia berlandieri Moq. https://s3.amazonaws.com/huhwebimages/A76131DCFDBE4D1/type/full/36984.jpg (consulted January, 2019). [ Links ]

Costea, M., A. Sanders and G. Waines. 2001. Preliminary results towards a revision of the Amaranthus hybridus complex (Amaranthaceae). Sida 19: 931-974. [ Links ]

CVH. 2004-2015. Chinese Virtual Herbarium. http://www.cvh.ac.cn/ms/PE/00024069 (consulted January, 2019). [ Links ]

Das, S. 2016. Amaranthus: A Promising Crop of Future. Springer Nature. Singapore, Singapore. 207 pp. [ Links ]

Eliasson, U. H. 1985. Identity and taxonomic affinity of some members of the Amaranthaceae from the Galápagos Islands. Botanical Journal of the Linnean Society 91(3): 415-433. DOI: https://doi.org/10.1111/j.1095-8339.1985.tb01011.x [ Links ]

Hardion, L., R. Verlaque, M. S. Vorontsova, I. Combroux, C.-W. Chen T. Takamizo and B. Vila. 2017. Does infraspecific taxonomy match species evolutionary history? A phylogeographic study of Arundo formosana (Poaceae). Botanical Journal of the Linnean Society 183(2): 236-249. DOI: https://doi.org/10.1093/botlinnean/bow006 [ Links ]

Henrickson, J. 1999. Studies in new world Amaranthus. Sida 18(3): 783-807. [ Links ]

Hernández-Ledesma, P., W. G. Berendsohn, T. Borsch, S. Von Mering, H. Akhani, S. Arias, I. Castañeda-Noa, U. Eggli, R. Eriksson, H. Flores-Olvera, S. Fuentes-Bazán, G. Kadereit, C. Klak, N. Korotkova, R. Nyffeler, G. Ocampo, H. Ochoterena, B. Oxelman, R. K. Rabeler, A. Sanchez, B. O. Schlumpberger and P. Uotila. 2015. A taxonomic backbone for the global synthesis of species diversity in the angiosperm orden Caryophyllales. Wildenowia 45(3): 281-383. DOI: https://doi.org/10.3372/wi.45.45301 [ Links ]

Howell, J. T. 1933. The Amaranthaceae of the Galapágos islands. Proceedings of the California Academy of Sciences, ser. 4, 21: 87-116. [ Links ]

Iamonico, D. 2011. On the presence of Amaranthus polygonoides L. (Amaranthaceae) in Europe. Phyton 50(2): 205-219. [ Links ]

Iamonico, D. 2014a. Lectotypification of Linnaean names in the genus Amaranthus L. (Amaranthaceae). Taxon 63(1): 146-150. DOI: https://dx.doi.org/10.12705/631.34 [ Links ]

Iamonico, D. 2014b. Amaranthus gangeticus (Amaranthaceae), a name incertae sedis. Phytotaxa 162(5): 299-300. DOI: https://dx.doi.org/10.11646/phytotaxa.162.5.2 [ Links ]

Iamonico, D. 2015a. Taxonomic revision of the genus Amaranthus (Amaranthaceae) in Italy. Phytotaxa 199(1): 1-84. DOI: https://doi.org/10.11646/phytotaxa.199.1.1 [ Links ]

Iamonico, D. 2015b. Amaranthaceae Juss. In: Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity. http://ww2.bgbm.org/EuroPlusMed/PTaxonDetail.asp?NameCache=Amaranthus&PTRefFk=7300000 (consulted January, 2019). [ Links ]

Iamonico, D. 2016a. Nomenclature survey of the genus Amaranthus (Amaranthaceae). 3. Plant Biosystems 150(3): 519-531. DOI: https://dx.doi.org/10.1080/11263504.2014.987188 [ Links ]

Iamonico, D. 2016b. Nomenclature survey of the genus Amaranthus (Amaranthaceae). 4. Detailed questions arising around the name Amaranthus gracilis. Botanica Serbica 40(1): 61-68. [ Links ]

Iamonico, D. 2016c. Nomenclature survey of the genus Amaranthus (Amaranthaceae). 5. Moquin-Tandon’s names. Phytotaxa 273(2): 81-114. DOI: https://dx.doi.org/10.11646/phytotaxa.273.2.1 [ Links ]

Iamonico, D. 2017. Amaranthus L. In: Pignatti, S. (ed.). Flora d’Italia 2. Edagricole. Bologna, Italy. Pp. 217-231. [ Links ]

Iamonico, D. 2020. A nomenclature survey of the genus Amaranthus (Amaranthaceae). 7. Willdenow’s names. Willdenowia 50(1): 147. DOI: https://doi.org/10.3372/wi.50.50114 [ Links ]

Iamonico, D. and G. Galasso. 2018. New nomenclatural changes for hybrids of Amaranthus (Amaranthaceae s. str.). Phytotaxa 340(2): 196-196. DOI: https://doi.org/10.11646/phytotaxa.340.2.11 [ Links ]

Iamonico, D. and J. Palmer. 2020. Nomenclature survey of the genus Amaranthus (Amaranthaceae). 6. Names linked to the Australian flora. Australian Systematic Botany 33(2): 169-173. DOI: https://doi.org/10.1071/SB18062 [ Links ]

Jarvis, C. 2007. Order out of chaos: Linnaean plant names and their types. Linnean Society of London and The Natural History Museum. London, UK. 1016 pp. [ Links ]

JSTOR. 2019a. JSTOR Global Plant, Type of Scleropus urceolatus Ands. https://plants.jstor.org/stable/10.5555/al.ap.specimen.s-r-5637?searchUri=plantName%3D%2522Scleropus%2Burceolatus%2522%26syn%3D1 (consulted January, 2019). [ Links ]

JSTOR. 2019b. JSTOR Global Plant, Type of Scleropus urceolatus Ands. Type of Sarratia berlandieri Moq. https://plants.jstor.org/stable/10.5555/al.ap.specimen.ph00022348?searchUri=scope%3Dplants%26so%3Dps_group_by_genus_species%2Basc%26Query%3DSpecies%3Aberlandieri%2520AND%2520Genus%3ASarratia%2520AND%2520%28raw_type%3Avisual%2520OR%2520ResourceType%3Aspecimens%29 (consulted January, 2019). [ Links ]

Kellogg, E. S. 1988. Amaranthaceae Juss. In: Howard, R. A. (ed.). Flora of the Lesser Antilles 4. Arnold Arboretum, Harvard University. Cambridge USA. Pp. 142-173. [ Links ]

Li, F.-Z. and C. K. Ni. 1981. A new species of Amaranthus from Shantung. Acta Phytotaxonomica Sinica 19(1): 116. [ Links ]

Li, Z.-H., Song, B.-H. and F. Z. Li. 2002. The identity of Amaranthus taishanensis. Acta Phytotaxonomica Sinica 40(4): 383-384. [ Links ]

Linnaeus, C. 1759. Plantarum Jamaicensium Pugillus. G. Elmgren. Upsaliae, Sweden. 32 pp. [ Links ]

McNeill, J. 2014. Holotype specimens and type citations: General issues. Taxon 63(5): 1112-1113. DOI: https://doi.org/10.12705/635.7 [ Links ]

MNHN. 2019. Sarratia berlandieri Moq., Muséum National D’Histoire Naturelle. https://science.mnhn.fr/institution/mnhn/collection/p/item/list?specificEpithet=berlandieri&genus=Sarratia (consulted January, 2019). [ Links ]

Moquin-Tandon, C. H. B. A. 1849. Amaranthaceae Juss. In: Candolle, A. de (ed.). Prodromus Systematis Regni Vegetabilis 13(1). Sumptibus Victois Masson. Parisiis, France. Pp. 231-424. [ Links ]

Mosyakin, S. L. and K. R. Robertson. 1996. New infrageneric taxa and combinations in Amaranthus (Amaranthaceae). Annales Botanici Fennici 33: 275-281. [ Links ]

Mosyakin, S. L. andK. R. Robertson . 2003. Amaranthus L. In: Flora of North America Editorial Committee (eds.). Flora of North America North of Mexico (Magnoliophyta: Caryophyllidae, part 1) 4. Oxford University Press. Oxford, UK. Pp. 410-435. [ Links ]

NHM. 2020. Natural History Museum, Data Portal. Sloane Herbarium, ID: 685. https://data.nhm.ac.uk/dataset/sloane-herbarium/resource/612007dd-ce3f-4077-b745-793b9f4d780d/record/692 (consulted January, 2019). [ Links ]

NYBG. 2020. New York Botanical Garden. C. V. Starr Virtual Herbarium. Sarratia berlandieri Moq. http://sweetgum.nybg.org/science/vh/specimen-details/?irn=1152398 (consulted January, 2019). [ Links ]

Sloane, H. 1707. A voyage to the Islands Madera, Barbados, Nieves, S. Christophers and Jamaica, with the Natural History of the Herbs and Trees, Four-footed Beasts, Fishes, Birds, Insects, Reptiles, & C. of the last of those Islands 1. B.M. London, UK. 264 pp. [ Links ]

Stafleu, F. A. and R. S. Cowan. 1976. Taxonomic Literature, 2nd ed. 1 (A-G). Scheltema & Holkema. Bohn, Germany and Utrecht, Sweden. 1136 pp. [ Links ]

Standley, P. C. 1917. Amaranthaceae. North American Flora 21(2): 1-74. [ Links ]

Thellung, A. 1914. Amaranthus L. In: Ascherson, P. and P. Graebner (eds.). Synopsis der Mitteleuropäischen Flora 5. Verlag Von Gebrüder Borntraeger. Leipzig, Germany. Pp. 225-356. [ Links ]

Thiers, B. 2020+. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/ih/ (consulted January, 2019). [ Links ]

Turland, N. J., J. H. Wiersema, F. R. Barrie, W. Greuter, D. L. Hawksworth, P. S. Herendeen, S. Knapp, W.-H. Kusber, D.-Z. Li, K. Marhold, T. W. May, J. McNeill, A. M. Monro, J. Prado, M. J. Price and G. F. Smith (eds.). 2018. International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017. Regnum Vegetabile 159. Koeltz Botanical Books. Glashütten, Germany. DOI: https://doi.org/10.12705/Code.2018 [ Links ]

Uline, E. B. and W. L. Bray. 1894. A preliminary synopsis of the North American species of Amaranthus. Botanical Gazzette 19: 313-320. [ Links ]

Waselkov, K. 2013. Population Genetics and Phylogenetic Context of Weed Evolution in the Genus Amaranthus: Amaranthaceae). Ph.D. thesis, Washington University. St. Louis, USA. 271 pp. [ Links ]

Waselkov, K., A. S. Boleda and K. M. Olsen. 2018. A Phylogeny of the Genus Amaranthus (Amaranthaceae) Based on Several Low-Copy Nuclear Loci and Chloroplast Regions. Systematic Botany 43(2): 439-458. DOI: https://doi.org/10.1600/036364418x697193 [ Links ]

Funding

No official fund there are for this research.

Author contributions

DI conceived and designed the study, reviewed the collections, wrote the manuscript, edited the review and approved the final manuscript.

Received: March 02, 2020; Revised: April 03, 2020; Accepted: April 10, 2020

2 Author for correspondence: d.iamonico@yahoo.it

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