BOTN 201 - Department of Biology - TAMU
Images of the Navasota Flora - 19 March 1995
Spring is well advanced in the Navasota Valley and many angiosperms are taking advantage of the current warm, moist conditions to move into reproductive mode. Here is the status of several local species as of the 19th of March, 1995.
The oaks (Quercus - Fagaceae - Hamamelidae)) are a dominant element of the Navasota Flora. The water oak, Quercus nigra , is the first flower. Relying on the wind for microgametophyte transfer, the staminate inflorescence or catkin (detail) is more evident to the casual observer than the pistillate flowers of these monecious trees.
Antennaria fallax is one of the first native species of the Asteraceae (Compositae) to flower each spring in the Navasota Valley. The terminal cluster of capitula (tight 'head'-like inflorescences of very small flowers) provide an image that relates to the local name for this plant - 'Pussy's toes'. A close look at a single capitulm, reveals standard features of this important family. Antennaria also shows the heavy pubescence that is typical of its Tribe (group of related genera) - the Inulae.
While the most conspicuous member of the Fabaceae in our Spring flora, Lupinus texensis, is just starting to produce inflorescences, our common vetch, Vicia ludoviciana, is in full bloom. The genus Vicia is marked, within the context of the Navasota Flora, by its pinnately compound leaves which terminate in a tendril. The vetch flower shows the classic structure of the Fabaceae or Bean Family with the conspicuous uppermost 'banner' petal, the lateral 'wing' petals, and the lower two petals connate to form the 'keel'.
The Mexican Plum, Prunus mexicana is now leafing out. Its flowers, at anthesis two weeks ago (see here), are now showing loss of the androperianth and maturation of the gynoecium. Check here for a look at the drupe (or 'Mexican Plum') at its early stages of development.
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Last updated by HDW on 21 March 1995