Podocarpus roraimae

Pilg. (1913), p. 299

Common names

Ai-yek (Venezuela).

Taxonomic notes

Type: Guyana, Cuyuni Mazaruni, Pakaraima Mountains, Mt. Roraima, 2040-2255 m, E. H. G. Ule s.n. (holotype B). See POWO for synonymy.

Description

Shrubs, or small trees to 10 m tall and 30 cm dbh, with a dense and often straggling crown of spreading branches. Twigs round, finely grooved between leaf bases. Foliage buds subglobose, 3-5 mm across; with free, erect, acute scales; the outer scale often morphed into or accompanied by reduced leaflets much longer than normal bud scales. Leaves on mature plants 20-30 × 4-7 mm, gradually narrowing to a short-petiolate base, more abruptly ending at an acute or obtuse apex; texture coriaceous, margins revolute, color dark green above and pale or glaucous green below; upper (adaxial) midrib obtusely raised to nearly flat with a central groove; on lower side prominently raised; stomata abaxial, in many intermittent lines on either side of midrib. On juvenile plants leaves spreading, more linear, up to 60 mm long. Pollen cones axillary, solitary, sessile, subtended by scales at base, cylindrical at maturity, 15-20 × 2.5-3 mm; microsporphylls triangular with 2 globose pollen sacs. Seed cones axillary, solitary on a slender 5-10 mm peduncle; receptacles 6-8 mm long, comprised of 2 unequal bracts, slightly swollen at maturity and turning red. Seeds single, ca. 8 × 5 mm including epimatium, ovoid with a distal crest (Farjon 2010).

Distribution and Ecology

Guyana (Mt. Roraima) and Venezuela (several isolated peaks in Amazonas and Bolivar). Only known from sandstone tepuis at elevations of 1800-2700 m, with a very moist and often foggy climate, usually found as small stands of shrubs and trees amidst ombrotrophic bogs dominated by forbs with interspersed low scrub and woodland. Shrubs are typical in open terrain, while in woodland and forest it often becomes a small tree. Associates include Podocarpus steyermarkii and P. tepuiensis; these have leaves with an adaxial midvein groove, and have respectively larger and smaller leaves. Due to its remote occurrence in areas with minimal human disturbance, the species is not of conservation concern (Farjon 2010).

Remarkable Specimens

Ethnobotany

No uses have been recorded (Farjon 2010).

Observations

Remarks

The epithet refers to the type locality, on Mt. Roraima, a large tepui located at the junction of Brazil, Guyana and Venezuela.

Citations

See also