Gundlachia
Proc. Amer. Acad. Arts 16: 100. 1880.
Taxon | Illustrator ⠉ | |
---|---|---|
Oclemena acuminata Ionactis alpina Gundlachia triantha | Yevonn Wilson-Ramsey Barbara Alongi John Myers |
Shrubs, [8–] 10–100 [–200] cm. Stems erect to ascending, abundantly branched [simple], glabrous or papillate-scabrous [scabrous, sparsely hairy, often gland-dotted], usually resinous. Leaves cauline (evenly spaced [clustered at branch tips]); sessile [short-petiolate]; blades (midveins obscure [prominent]) filiform [linear, elliptic, or obovate] (flat to involute-terete), margins entire [minutely toothed] (apices obtuse to acute, sometimes apiculate), faces sparsely hairy [glabrous, papillate, scabrous], often gland-dotted [sometimes in deep pits], resinous. Heads discoid [radiate], usually clustered at branch tips, clusters few [numerous and sometimes hidden by surrounding leaves], in cymiform or racemiform [paniculiform to corymbiform] arrays. Involucres turbinate [cylindric to nearly hemispheric], (4–6 ×) 2–3 [–8] mm. Phyllaries 8–30 in [2–] 3–4 [–5] series (mostly tan), 1-nerved (midveins evident and expanded apically, less evident to obscure proximally); mostly keeled, except innermost [convex to flat], [ovate] narrowly ovate to lanceolate or obovate [linear-lanceolate], unequal, chartaceous proximally or throughout, outer sometimes herbaceous or herbaceous-tipped, margins scarious (entire, lacerate to fimbriate), (apices acute to rounded [acuminate]) faces glabrous or sometime pustulate, usually resinous. Receptacles flat to convex, pitted, epaleate (pit borders short-scaly [short-awned]). Ray-florets 0 [–12, pistillate, fertile; corollas pale-yellow to white]. Disc-florets 3–7 [–50], bisexual, fertile; corollas pale-yellow [yellow to white], tubes often longer than narrowly campanulate [tubular, distally dilated] throats, lobes 5, spreading to recurved [laxly erect], narrowly lanceolate to triangular (unequal); style-branch (linear-lanceolate to ovate, 0.9–2.5 mm) appendages linear to subulate. Cypselae (tan [to coppery bronze]) turbinate [cylindric, elliptic, or obovoid], mostly 5–8 nerved, faces sparsely to densely hairy; pappi persistent, of 40–50 whitish or tan, barbellate, apically attenuate bristles in 1 series. x = 9.
Distribution
Tex., n Mexico, Bahamas, West Indies, South America (n Venezuela)
Discussion
Species 6 (1 in the flora).
Gundlachia grows in arid habitats in rocky to sandy soils.
Phylogenetic analyses (L. E. Urbatsch et al. 2003) demonstrated the polyphyly of genus Xylothamia G. L. Nesom, Y. Suh, D. R. Morgan & B. B. Simpson and showed that some species assigned there are more closely related to Gundlachia.
Selected References
None.
Lower Taxa
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