BOTN 201 - Department of Biology Herbarium - TAMU
Images of the Navasota Flora - 9 July 1995

Eryngium yuccifolium (Apiaceae or Umbelliferae) is a 'signal' species for relatively undisturbed, prairie habitat within the leaf of this species is atypical in that it has the look of a monocot. As indicated by a look at relatives, such as E. hookeri or Polytaenia nuttallii, via reduction of peduncles and pedicels to produce young inflorescence shows styles emerging well prior to the androecium, which is only evident when the inflorescence is at Sequenced anthesis is also evident in another native perennial, H. annuus, and also typical of its family, the Asteraceae (Compositae) - a family often marked by Helianthus as the 'Sunflower' family. The 'sunflower' is actually a 'composite' inflorescence of small flowers aggregated to form a capitulum similar to that produced by Eryngium species. This radiate inflorescence is, however, composed of two types of flowers - 'disk' flowers at the center and 'ray' flowers at the periphery. A long section of the H. hirsutus phyllaries. This sectional image also shows synanthery or fusion of the androecium at the anthers to produce a tubular structure. The anthers dehisce or open inwards and, as the style elongates during floral development, it pushes pollen toward the top of the tube, eventually producing Return to the Navasota Flora Homepage
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Last updated by HDW on 11 July 1995