Shrublet 0-08-0-16 m tall, forming clumps or cushions c. 15 mm in diam., with branches strict, mostly pseudo-dichotomous, or the outer decumbent but not rooting. Stems orange-brown, 4-lined and compressed when young, soon terete, cortex exfoliating irregularly; internodes 1-4 mm long. Leaves sessile, erect to closely imbricate, scarcely outcurving, not tetrastichous, persistent; lamina 4-7 x 0.6-0.8 mm, linear (upper) to acerose, incurved-canahculate, cucullate, midrib not impressed, margin narrowly hyaline, concolorous, both surfaces dull, glaucous, subcoriaceous?; apex subacute to obtuse, base parallel, not clasping, pairs united to form very narrow interfoliar ridge; basal vein 1, unbranched; laminar glands dense, large, impressed beneath. Inflorescence 1-flowered, with pseudo-dichotomous branches from node below; pedicel 3-4 mm long, slender; upper leaves not transitional. Flowers 8-10 mm in diam., obconic (?). Sepals 4-5 x 0.8-1.3 mm, narrowly oblong, acute, incurved above; veins 5, unbranched, all prominent; glands mostly linear but striiform to punctiform near hyaline margin. Petals 6-8 x 2 mm,c. 1-5 x sepals, oblong-obovate; apiculus acute; glands few, punctiform. Stamens c. 25, longest 4-5 mm long, c. 0.65 x petals. Ovary c. 1 x 0.5 mm, ellipsoid; styles 3, 2-2.5 mm long, c. 2-2.5 x ovary, outcurving to erect; stigmas broadly capitate. Capsule 4-5 x 2-2.5 mm, narrowly ellipsoid, obtuse, exceeding sepals. Seeds 1-2 mm long, ecarinate; testa finely scalariform-reticulate.
In rocky páramo, muddy places in high-rainfall areas; 3000-3900 m.
Colombia (Magdalena); confined to the Sierra de Santa Marta.
H. martense is a high-altitude derivative of the 'laricoides' form ofH, laricifolium. As a result of its dwarf, caespitose habit, however, the non-pseudo-dichotomous parts are much reduced, most of the clump being formed by pseudo-dichotomous (inflorescence) branching. The branches of a pseudo-dichotomy, however, usually bear lateral flowering branches.