Floral development and anatomy of two species of Aechmea (Bromeliaceae, Bromelioideae)

• Published in: Botanical journal of the Linnean Society Vol. 194; no. 2; pp. 221 - 238
• Main Authors: Santa-Rosa, Sandra, Versieux, Leonardo M, Rossi, Monica Lanzoni, Martinelli, Adriana Pinheiro
• Format: Journal Article
• Language: English
• Published: UK Oxford University Press 01.10.2020
• Subjects: monocotyledons; morphology; septal nectary; Poales; conduplicate-spiral stigma; petal appendage
• DOI: 10.1093/botlinnean/boaa033
• ISSN: 0024-4074

Abstract Aechmea (Bromeliaceae) is a large genus with controversial systematics and distinct flower shapes and pollinators. We explored floral anatomy and development in two Aechmea spp. belonging to different subgenera to contribute useful information on reproductive biology and taxonomy. We examined floral buds using scanning electron and light microscopy to characterize the development of septal nectaries, petal appendages, ovules, stamens and carpels. In A. gamosepala, we confirmed that the petal appendages develop late, whereas in A. correia-araujoi they develop earlier during floral development. Petal appendage formation included positional changes, possibly affecting floral attributes and visitation by insects, rather than vertebrates. Nectar is released through three basal orifices distally on the ovary, and here we document the link between the nectary region, through discrete canals, upward to the conduplicate lobes of the wet stigma. Improved understanding of the floral development and morphology of Aechmea may help to explain the existence of polymorphic flowers in this genus and may have implications for studies on interactions with pollinators and systematics.