Monographs Details – Ericaceae

Monographs Details:

Authority:

Pedraza-Peñalosa, Paola. 2010. (Ericaceae, Vaccinieae). Fl. Neotrop. Monogr. 108: 1-126. (Published by NYBG Press)

Family:

Ericaceae

Scientific Name:

Disterigma panamense Standl.

Synonyms:

Disterigma luteynii Wilbur

Description:

Species Description - Epiphytic shrubs, wiry and scandent. Young branchlets ridged, pubescent, the hairs eglandular, light brown, the indumentum of the mature branches similar but glabrate. Leaves 6–10 per cm, apparently distichous, diffuse or rarely patent; petiole 0.8–1.5 mm long, glabrate or puberulous, the hairs eglandular or glandular; lamina oblanceolate or obtrullate, (0.8–)0.9–1.5 × 0.2– 0.4(–0.5) cm, basally cuneate, marginally entire, apically ciliolate with minute eglandular hairs (especially in young leaves), apically blunt-acute or sometimes acute, adaxially glabrate with minute eglandular hairs over the base and midvein, abaxially glabrate with glandular hairs, the venation adaxially obscure or hyphodromous with the midvein impressed, abaxially 3-nerved with the midvein raised. Axillary and subterminal solitary flowers; bracts 2–6 or occasionally completely absent when the flowers subterminal, chartaceous, ovate, 0.8–1.5 × 0.7–2.1 mm, marginally minutely ciliolate with eglandular hairs, apically obtuse, abaxially glabrous; pedicel 0.5–2 mm long, reduced and hidden by overlapping bracts, glabrate with eglandular hairs; differentiated apical bracteoles 2, distinct, chartaceous, enveloping entire calyx tube or to part of calyx lobes, covering 42–70% of calyx, ovate or transverse-elliptic, 1.5–2.2(–3) × 2.1–3.6 mm, marginally ciliolate with eglandular hairs, apically obtuse, the surface smooth, abaxially glabrous or rarely glabrate with eglandular hairs, adaxially glabrous. Flowers 4-merous. Calyx aestivation imbricate, campanulate, (2.8–)3–3.6(–4.2) mm long; tube terete, 0.9–1.5 mm long, abaxially glabrous; limb 1.8–2.8 mm long, abaxially glabrous or rarely apically glabrate with eglandular hairs, adaxially glabrous; lobes triangular, 1.4–2 (–2.5) × 1–1.6 mm, marginally ciliolate with eglandular hairs, apically acute; sinuses acute (V-shaped). Corolla white, sometimes with pink hue, thin-fleshy, bistratose, tubular or narrowly urceolate, 5.6–6(–6.5) mm long, 2.1–2.5 mm diam., ca. 1.8 mm wide at throat, abaxially glabrous, adaxially glabrate with very few hairs, sometimes as short as 0.15 mm long, and especially concentrated on the lobes; lobes 1.3–1.5 × 1–1.4 mm, apically acute, adaxially rugose. Stamens 8, 5– 5.3(–6) mm long, included; filaments distinct, straight, ± linear with parallel sides, 2.2–3.5 mm long, abaxially and adaxially puberulous (apically); anthers distinct, papillae only on thecae or also on the tubules (especially at base) and then inconspicuous; thecae not basally prognathous, 1–1.5 mm long, with or without basal appendage; tubules 2, distinct, 1.6–2.2 mm long, dehiscing introrsely by longitudinal slits, 0.4–0.8 mm long. Ovary 4–locular; style 4.5–6 mm long, exserted or included. Berry white, 5.6–7.8 mm diam., the persistent calyx lobes erect or spreading, becoming succulent (at least at base), same color as mature berry; embryo white.

Distribution and Ecology - This rare species is known from a few collections from central and western Panama; one collection from Chocó, Colombia; and another collection from Carchi, Ecuador (Fig. 26). It grows in shrubby vegetation in the tropical rainforest and premontane cloud forest at 660–1675 m. Flowering year-round; fruiting in Jan, Apr, Oct, and Dec.

Local Names and Uses - This species is known as "pasino" in Ecuador, where the plant is crushed into paste that is placed on the forehead to treat fever.

Discussion:

Although the populations of Disterigma panamense with narrow leaves show superficial similarity to the leaves of D. hammelii, the differences between them are many. Disterigma panamense (Fig. 34E) is easily recognized by its apparently distichous and oblanceolate or obtrullate leaves; solitary flowers that are axillary and subterminal; imbricate calyx aestivation, acute calyx sinuses; white, short, tubular or narrowly urceolate and adaxially glabrate corollas; and white fruits and embryos. Disterigma luteynii and D. panamense are not different enough to be considered separate species; they have overlapping floral and vegetative dimensions and share many important morphological characters such as leaf shape and apex, position of the solitary flowers, bracteole appearance and arrangement on the pedicel, floral merosity, and calyx aestivation, among others. Therefore, the status of D. luteynii, being the most recent name, can no longer be maintained. However, some specimens described under D. luteynii, once a species thought to be endemic to Cerro Azul and Cerro Jefe in the Prov. Panama, differ from the rest of D. panamense in usually having leaves shorter (three or less times longer than broader vs. five or at least three times longer than broader respectively) and wider ([0.2–]0.3–0.4[–0.5] cm vs. 0.2–0.3[0.4] cm), the calyx limb shorter (1.8–2 mm vs. 2.5–2.8 mm long), and the calyx lobes shorter (1.4–1.7 mm vs. 2[–2.5] mm). The relatively larger leaves from Cerro Jefe come from plants in premontane cloud forest with many small trees and shrubs and unusually open canopy.

Common Names:

pasino