Monographs Details: Guaicaia
Authority: Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Description:Genus Description - Capitula parva homogama 18—22-flores; involucris obconicis vel anguste rhomboideis; receptaculo convexo, glabro, epaleaceo; phyllariis gradatis minusve acutis; corollis bilabiatis; granis pollinis tricolporatis, trisulcatis, naviculoideis vel elliptico-oblongis, ad apices polares conspicue incrassatis, minutissimis muricu-latis, 26-30 x 16-22 µ.
Frutex; axibus monopodialibus; petiolis foliorum semivaginatis; unitypico; gen. Glossariono aflini.
Type. Guaicaia bilabiata Maguire.
The name is derived from that of the Guaica Indians, whose assistance made possible the collection of the material here described.
Guaicaia is the fourth unitypic genus of the Mutisieae to be described from Guayana. One’s immediate reaction is to be impatient with genera of but a single species, but their individuality here is such that arbitrarily to assign them to existing larger recognized genera would be to destroy distinction among the hierarchy of genera of Guayana Mutisieae as a whole and to deny biological verity.
This phenomenon of extreme segregation of genera may be explained by longtime geographic and ecologic isolation of the many plateaus of Guayana and, hence, independent genetic development without contamination by intergression.
In 1964, while a member of the Brazilian-Venezuelan Boundary Commission,
J. Ewel with much strenuous effort obtained a collection of several hundred plants. It is my privilege to review this collection. Among the specimens obtained are two shoots of Glossarion with immature heads. Leaves ally the specimens with
G. rhodcmthum. However, the capitulae are excessively tomentose, and the subtending cephalar bracts are excessively long and attenuately lanceolate. The collection evidently represents a variety of this species and is here so proposed.