BOTN 201 - Department of Biology - TAMU
Images of the Navasota Flora - 28 May 1995

Local populations of the American Beauty Berry are in full flower this week. An important understory shrub of both upland (Post Oak) and mesic (Water Oak) woodlands, Callicarpa americana (Verbenaceae), is not named for its flowers. After anthesis, the sympetalous corollas fall to reveal a developing gynoecium cupped within the unit calyx. In contrast to most elements of the Verbenaceae in the Navasota Flora, these develop into baccate fruits that produce an attractive display when fully mature during the Fall months.

An inhabitant of the aquarium in Dr. Wilson's lab produced an inflorescence this week. A close look at the upper-most flowers, those at anthesis, and those showing developing gynoecia, at the base of the inflorescnce, shows six stamens and an tricarpellate, apocarpous gynoecium. These produce follicles at maturity. These features suggest a basal element of the Lilipopsida. The plant is a member of the genus Aponogeton, of the monotypic Aponogetonaceae. Placed in the basal subclass Alismatidae, these plants show both structural and habitat (aquatic) links to the archaic monocot realm. Restricted to the Old World tropics and South Africa, Aponogeton is limited to a highly restricted habitat (cultivation in aquaria) in the Navasota Valley. This, unfortunately, is not always the case for introduced, aquatic angiosperms.

Another exotic came into flower this week. Among the cluster of plants growing in a greenhouse flat used to demonstrate insectivorous elements of the Rosidae (Nepenthales), this one - while insectivorous - is clearly not an element of the Rosidae. Sympetaly suggests the Asteridae and zygomorphy with a spur suggests the Scrophulariales. A close look at the very unusual structure of the reproductive parts (see Cronquist's 'Integrated system', p. 973 or Zomlefer's 'guide', p. 257) shows distinctive features of the Lentibulariaceae. While this genus - Pinguicula (Butterwort) - is not found in the Navasota flora, we do have several species of the related genus - Utricularia (Bladderwort).

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Last updated by HDW on 3 June 1995