Morphology and development of the female flowers in Geonoma interrupta (Arecaceae)

Abstract

Morphology and development of the female flowers in Geonoma interrupta are described and compared with other taxa within Arecaceae. Inflorescences are pleiothyrses. Cincinni are immersed in pits and arranged according to the Fibonacci pattern along the rachillae. The gynoecium is composed of three free carpels in early stages and later becomes pseudomonomerous. Two carpels are sterile; they develop to different degrees and are commonly unequal in size. The fertile carpel contains a single, crassinucellate, anatropous ovule. Styles are formed in each carpel. The style of the fertile carpel becomes basifixed as the ovary enlarges. The stigmas remain free and plicate during development and expose unicellular papillae at anthesis. Pollen tube transmitting tracts and a compitum are present in the ventral slits of the stigmas and the postgenitally united styles during anthesis. A septal nectary is formed by incomplete union of the flanks of the carpels at the base of the gynoecium, and nectar is secreted from an epithelium. It is suggested that in Geonoma as a whole, the attraction of pollinators to female flowers is due to a combination of nectar reward and partial mimicry of male flowers.

Morphoanatomy of the flower of Syagrus inajai (SPRUCE) Becc. (Arecaceae- Arecoideae- Attaleinae), Amazon

“…Syagrus inajai presented a secretory epidermis, in the septa (septal nectary), similar to that observed in Euterpe precatoria, in the Subtribe Geonomeae, Asterogyne, Pelagodoxa, Sommieria and in Cocos nucifera and Licuala peltata, which the authors termed septal nectary (Kuchmeister et al, 1997;Stauffer et al, 2002;Stauffer et al, 2004;Guevara and Jáuregui, 2008;Stauffer et al, 2009). The septal nectary is formed by the incomplete union of the carpel flanks (Weberling, 1992;Stauffer et al, 2004;Rudall et al, 2011).…”

Biologia reprodutiva de Geonoma brevispatha Barb. Rodr. (Arecaceae) em mata de galeria inundável em Uberlândia, MG, Brasil

“…Entretanto, a primeira fl or pistilada de uma mesma infl orescência abre-se aproximadamente 15 dias após a abertura da última fl or estaminada. Stauffer et al (2002) observaram essa mesma seqüência de abertura em um estudo com Geonoma interrupta, na Venezuela.…”

“…Dessa forma, ocorre dioicia funcional e, por isso, para a produção de sementes é necessária a polinização cruzada (Scariot et al 1991, Stauffer et al 2002. Cruden (1988) defi ne a dioicia funcional como sendo a alternância das fases estaminadas e pistiladas no mesmo indivíduo, assegurando a separação das fases sexuais.…”

Estructura floral de dos especies de Trachycarpeae (Arecaceae)

“…En la familia Arecaceae son conocidos los trabajos morfológicos y anatómicos de desarrollo floral con fines taxonómicos (Baker, Dransfield, Harley, & Bruneau, 1999;Kahn & Gluchy, 2002;Stauffer, Rutishauser, & Endress, 2002;Stauffer & Endress, 2003;Rudall, Abranson, Dransfield, & Baker, 2003). Dentro de la subfamilia Coryphoideae se ha utilizado la morfo-anatomía de los órganos reproductivos para explicar entre otras cosas, relaciones filogenéticas y aspectos de la biología reproductiva.…”