Ledothamnus decumbens Maguire, Steyerm. & Luteyn
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Authority
Luteyn, James L., et al. 1995. Ericaceae, Part II. The Superior-Ovaried Genera (Monotropoideae, Pyroloideae, Rhododendroideae, and Vaccinioideae P.P.). Fl. Neotrop. Monogr. 66: 560. (Published by NYBG Press)
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Family
Ericaceae
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Scientific Name
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Type
Type. Venezuela. Bolívar: Chimanta Massif, Central Section, headwaters of the Rio Tirica, 2200 m, 11 Feb 1955 (fl, fr), Steyermark & Wurdack 737 (holotype, NY; isotypes, AAU, F, photo F neg. 59489, GH, K, US, VEN).
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Description
Species Description - Rhizomatous, decumbent, spreading to erect subshrub, 0.1-0.3(-0.5) m tall; mature stems subterete to terete, glabrous; bark ± smooth but coarsely cracking reticulately; twigs subterete, striate, glabrous. Leaves opposite to subopposite, imbricate, bases often equitant, appressed and usually restricted to tips of twigs, linear-oblong, 6-11 × 1-1.3 mm, base tapering imperceptibly into petiole, apex acute, mucronate into a long, translucent seta to ca. 0.8 mm long, actual margins usually not converging or overlapping but forming two parallel lines along the length of the leaf beneath (converging and then contiguous close to apex), apparent margins pectinate with sharp, translucent, eglandular (minutely glandular) setae to ca. 0.5 mm long with basal ones sometimes thinner and more ciliate, then branched, otherwise lamina glabrous; petiole barely distinguishable from lamina, but ca. 1-1.5 mm long, ciliate (Fig. 2F-G). Inflorescence axillary, flowers solitary; floral bract leaf-like in all aspects; pedicels subterete, ribbed to striate, (12-) 15-30 mm long, glabrous to weakly puberulent, also moderately to densely glandular-hispid (eglandular) with hairs to 1.8 mm long; bracteoles leaf-like but 2.5-6.0 mm long. Flowers 6-merous; calyx 5.5-8 mm long, lobes wide-spreading, linear-ovate, 5-7.5 mm long, acuminate, glandular-hispid dorsally and at margin and apex (eglandular); petals wide-spreading (corolla rotate), oblong-elliptic to obovate, 8-12 × 4-7 mm, rounded to obtuse, scarlet (or rose-salmon) when fresh, glabrous; stamens 6-8(-10) mm long; filaments 5.2-7(-9) mm long; anthers 1.8-2.5 mm long; ovary glabrous; style 2.3-3 mm long, glabrous. Capsule ovoid-globose, 5-6 mm diam.
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Discussion
Ledothamnus decumbens is characterized by its habit as a decumbent or spreading to erect subshrub, leaves with laminas tapering almost imperceptibly into the petioles, leaf margins ± pectinate with short, translucent, usually eglandular setae, long and glandular-hispid pedicels, calyx lobes glandular-hispid dorsally as well as at margin, and usually scarlet petals. Sometimes the uppermost leaves may have a few glandular setae; rarely the hairs of the apparent leaf margins are branched (Huber & Dezzeo 8585, NY). Huber et al. 10159 (NY) has calyx lobes with both glandular and eglandular pubescence on the same flower.
Many collections which show leaves somewhat more ovate, where the actual leaf margins converge and touch near the apex, and where petals are scarlet to salmon-rose color are probably the result of previous hybridizations (and back-crossing?) with L. luteus (e.g., Luteyn et al. 9505, NY; Huber, Steyermark & Luteyn 9067, NY). These can usually be determined, however, as L. decumbens without difficulty. A few other collections, with plants taller (to 4 dm), leaf lamina/petiole separation more clear, leaves more elliptic and marginally short-glandular-pubescent, calyx lobes glandular-hispid only along the margins, and petals a more salmon-yellow color are almost certainly hybrids with L. luteus (cf. especially Luteyn et al. 9498 and 9504, a population sample which included L. decumbens, L. luteus, and putative hybrids). -
Objects
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Distribution
Venezuela South America| Bolívar Venezuela South America|