Revista mexicana de biodiversidad
versión On-line ISSN 2007-8706
An anatomical floral study of some species of the genus Polianthes (Agavaceae), of both subgenus Polianthes and subgenus Bravoa (Agavaceae) was carried out, with the aim of testing the adequacy of the present subgeneric classification. The taxa studied of subgenus Polianthes were P. densiflora, P. nelsonii and P. platyphylla; and P. geminiflora var. geminiflora, P. howardii and P. multicolor of subgenus Bravoa. The anatomical characters between these species are similar, sharing with other members of the Agavaceae family the septal nectaries and the anatropous, bitegmic, and crassinucellated ovules. In the taxa of subgenus Bravoa, the filaments originate from the floral tube base, while in subgenus Polianthes they originate near the base of the internal tepals from the perianth tube. Before this anatomical study, it was considered that stamens originated in both subgenera at the base of the perianth tube, with their filaments remaining adnate to the perianth tube, getting separated at different levels. At interspecific level, the nectary/locule length ratio in P. howardii is larger than in the rest of the studied species.
Palabras llave : Bravoa; filaments; septal nectaries; anatropous ovules; abortive pollen; raphides.