Ledothamnus atroadenus Maguire, Steyerm. & Luteyn

  • 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)

  • Family

    Ericaceae

  • Scientific Name

    Ledothamnus atroadenus Maguire, Steyerm. & Luteyn

  • Type

    Type. Venezuela. Bolivar: Chimanta Massif, Abácapa-tepui, NW part of summit, 2125-2300 m, 13 Apr 1953 (fl, fr), Steyermark 74886 (holotype, NY; isotypes, F, photo F neg. 59488, US, photo NY neg. 12208, VEN). A second sheet of this number at F (#1739232) is L. luteus.

  • Description

    Species Description - Shrub 0.5-1.5(-3) m tall; mature stems terete, glabrous; twigs subterete, bluntly angled, smooth, glabrous. Leaves in whorls of 3-4, strongly imbricate, appressed to spreading, linear- to oblong-elliptic, or elliptic to ovate, (3.2-)4.5-7 × 1-1.5(-2.0) mm, base broadly cuneate, decurrent, apex acute, strongly keeled, provided with a sessile, ± triangular, red to black, callosed, terminal gland (apex with additional 4-7 tiny, triangular, reddish, sessile to short-stipitate glands which may fuse), apparent margin glabrous to minutely ciliate; petiole subterete, 0.5-2.0 mm long, glabrous (Fig. 2H). Inflorescence axillary, flowers 2-4; pedicels subterete, striate, ca. 10-13(-20) mm long, densely puberulent to short-white-pilose (with a few, short, reddish, apex minutely branched, eglandular setae ca. 0.2 mm long, or also glandular-hispid with hairs to 1 mm long); floral bract and bracteoles undifferentiated from leaves. Flowers 7-8-merous; calyx 4.5-8 mm long, lobes wide-spreading, linear-ovate, leaf-like in appearance, 4-7 mm long, acuminate, essentially glabrous or puberulent dorsally but margins minutely white-ciliate, with glands as in leaves (without apical, sessile gland but instead eglandular-mucronate, or nearly entire margin provided with tiny, sessile, ± triangular glands); petals spreading (corolla ± rotate), oblong-obovate, 10-15 mm long, rounded, margin ± erose, deep red to scarlet when fresh, glabrous; stamens ca. 5-5.2 mm long; filaments 3-3.5 mm long; anthers 1.8-2.5 mm long; ovary glabrous; style 2-3 mm long, glabrous. Capsule to 5 mm long.

  • Discussion

    Ledothamnus atroadenus is characterized by usually elongate, linear- to oblong-elliptic, ± glabrous leaves with a distinct, large, ± triangular-shaped, apical gland, eglandular to glandular-hispid pedicels, and dark red to scarlet flowers. Rarely (Steyermark & Wurdack 405, NY; Luteyn et al. 9543, NY, VEN; and Steyermark, Luteyn & Huber 129995, NY) the leaves are densely puberulent all over. A common variant shows leaves more appressed to the twigs, more ovate or elliptic, and with numerous (4-7), tiny, sessile to very short-stipitate glands near the apex which may coalesce. 1 suspect that this variant may be the result of past or current hybridizations with L. luteus, its closest relative, although the species can usually be identified without difficulty. Another curious variant, a possible hybrid with L. decumbens, is found on Huber et al. 10243 and Pipoly et al. 7226pp (NY) from the Chimanta Massif. Here, virtually all the leaves have mucronate tips except for a few of the very youngest, which have the terminal gland; otherwise the characters are those of L. atroadenus.

  • Objects

    Pending, J. L. Luteyn 9543, Ledothamnus atroadenus Maguire, Steyerm. & Luteyn, Ericaceae (261.0), Magnoliophyta; South America, Venezuela, Bolívar, Piar Mun.

    Specimen - 10108, J. A. Steyermark 74886, Ledothamnus atroadenus Maguire, Steyerm. & Luteyn, Ericaceae (261.0), Magnoliophyta, holotype; South America, Venezuela, Bolívar

  • Distribution

    Venezuela South America| Bolívar Venezuela South America|