Stomatochaeta
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Authority
Carlquist, Sherwin. 1957. Anatomy of Guayana Mutisieae. Mem. New York Bot. Gard. 9 (3): 441-476.
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Family
Asteraceae
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Scientific Name
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Discussion
The other genera of Gochnatinae considered here, Stomatochaeta, Chimantaea, and Quelchia, have some features seen in Stenopadus and Stifftia but are simpler in most features of floral vasculation. In the genus Stomatochaeta, S. crassifolia (fig. 107) shows a representative condition. The corollas (fig. 107A) have lateral veins which join at the tip of each lobe. In addition, subsidiary bundles, as in Stenopadus kunhardtii, branch from the laterals near the sinuses and extend for a distance up the lobes, terminating freely. No median veins are present. In the top of the achene (fig. 107 C), the pairs of adjacent laterals unite. Xylem of stamen traces often unites with that of laterals in the summit of the achene. In addition to the five bundles in the achene connected directly with corolla bundles, five other exterior bundles are present (fig. 107 C). These run from a plexus at the achene top to the base of the achene. The style of Stomatochaeta crassifolia contains two bundles (fig. 107 B). These enter the achene as a dorsiventral pair of interior achene bundles (fig. 107 C). In addition, a lateral pair of interior bundles is present in the achene (see also fig. 107 E, F). Near the base of the achene, the dorsiventral interior bundles unite with nearby exterior bundles (fig. 107 G), while the lateral pair forms a plexus with the ovule traces. At a lower level, this plexus of vascular tissue is broken up into strands which join exterior bundles (fig. 107 H). A cylinder of bundles enters the receptacle (fig. 107 I). In the configuration of vasculation at the achene base, Stomatochaeta crassifolia shows considerable resemblance to species of Stenopadus, S. cucullatus for example. The ovule trace in the specimen examined was found to be dichotomously branched (fig. 107 C).
The other species of Stomatochaeta examined, S. condensata, S. cylindrica, and S. cymbifolia, agreed with the pattern described for S. crassifolia except that subsidiary bundles were not found in corollas of these species; they are often not present in S. crassifolia. Likewise, an unbranched ovule trace, seen in S. crassifolia in addition to the dichotomous condition, was seen in material of these species.