Ledothamnus sessiliflorus N. E. Brown var. glaber N. E. Brown, Trans. Linn. Soc. London, Bot. 6: 45. 1901. Type: Venezuela. Bolívar: Upper part of ledge and summit, Mount Roraima, Autumn 1898 (fl), Quelch & McConnell 99 (holotype, K, photo NY s.n.). The protologue cites the collection as McConnell & Quelch 99; however, the label on the type sheet gives the names in the reverse order.
Wiry, rhizomatous shrublet to 3(-8)
dm tall; mature stems often gnarled, terete to subterete, striate
to ribbed, glabrous; bark cracking longitudinally; twigs subterete,
glabrous or puberulent. Leaves in whorls of 3-4, strongly imbricate,
ascending to strongly diverging from the stem, linear-oblong, ±
trigonous in cross-section, 3-6 x 0.8-1.2 mm, base broadly cuneate and
decurrent, apex acute, keeled (short-mucronate), apparent margins glabrous
or ciliate and then also bearing short, translucent, eglandular, acicular
hairs to 0.2 mm long, glabrate; petiole 0.5-1.2 mm long, glabrous
or puberulent. Inflorescence terminal, flowers solitary; pedicel
subterete, ca. 1.5-3 mm long, densely puberulent, also densely long-setose
with translucent, eglandular hairs to 1.7 mm long; floral bract and
bracteoles flat to concave above, ovate, 4-6 mm long, pubescent as leaves.
Flowers 6-8-merous; calyx campanulate, (6-)7-11 mm long, puberulent,
lobes spreading, ovate, 6.5-10 mm long, acuminate, similar in pubescence
to leaves; petals wide-spreading (corolla rotate), oblong-elliptic,
11-18 x 5-7 mm, rounded to obtuse, scarlet when fresh, glabrous;
stamens ca. 11 mm long; filaments 8-9 mm long; anthers 3-4
mm long; ovary glabrous; style (2-)3-4 mm long, glabrous.
Capsule oblong, 4-5 mm long.
Distribution (Map). Endemic to the Venezuelan Guayana, where it is known only from Cerro Roraima and the adjacent tepuis, in exposed, rocky crevices, slopes of "morros," and around rocky pools of water, at 2450 to 2800 m elevation. Flowering and fruiting throughout the year. Rare.