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 alaternoides (Kunth) Nied.

Synonyms:

Vaccinium alaternoides var. parvifolium Benth., Vacciniopsis tetramera Rusby, Disterigma popenoei S.F.Blake, Vaccinium alaternoides Kunth, Metagonia alaternoides (Kunth) Nutt.

Description:

Species Description - Epiphytic or terrestrial shrubs, scandent or erect, to 3 m tall. Young branchlets ridged, ± smooth, puberulous or villosulous, the hairs eglandular and white, the indumentum of the mature branches similar but glabrate. Leaves 1–3 per cm, spirally arranged, diffuse; petiole 1.5–3(–3.5) mm long, glabrate, the hairs eglandular; lamina sometimes succulent, ovate or elliptic, (0.8–)1.2–4(–4.7) × (0.4–)0.5–1.9(–3.5) cm, basally cuneate or less often obtuse, marginally entire or rarely crenulate, revolute toward base, apically ciliolate with eglandular hairs (especially in young leaves), apically blunt-acute, acute, or rarely obtuse, adaxially glabrate with eglandular hairs (especially over the midvein), abaxially glabrate with glandular and some eglandular hairs, the venation adaxially 3-nerved with the midvein impressed, abaxially hyphodromous or 3- nerved with the midvein raised. Inflorescences axillary, 3–9-flowered fascicles, sometimes solitary flowers also present; bracts 7–10, chartaceous, ovate, 0.8–2 × 0.6–2 mm, sometimes marginally ciliolate with minute eglandular hairs, apically obtuse, abaxially glabrous or glabrate with eglandular hairs; pedicel 1–3 mm long, reduced and hidden by overlapping bracts, glabrous or glabrate with eglandular and glandular hairs; differentiated apical bracteoles 2, distinct, chartaceous, enveloping entire calyx tube or to upper half of calyx lobes, covering 51–85% of calyx, ovate or suborbicular, 2.2–4 × 2.3–6 mm, marginally ciliolate with eglandular hairs and inconspicuous glandular hairs, apically obtuse, the surface smooth and often keeled, abaxially glabrous or glabrate with eglandular hairs, adaxially glabrous. Flowers 4-merous. Calyx aestivation valvate, campanulate, (2.5–) 3.5–5.5 mm long; tube slightly angled, (1.1–)1.7–2 mm long, abaxially glabrous or glabrate with glandular hairs; limb (1.4–) 1.6–3 mm long, abaxially glabrous or glabrate with eglandular hairs (especially apically), adaxially glabrous; lobes triangular, (0.6–)0.9–2 × 1–2.5 mm, rarely marginally ciliolate with eglandular hairs, apically acute; sinuses acute (V-shaped). Corolla pink or white, thin-fleshy, bistratose, tubular or narrowly urceolate (but mostly all drying tubular), 5.3–8.5(–10) mm long, 2.5–5 mm diam., 2.5–3.5 mm wide at throat, abaxially glabrate with inconspicuous eglandular and glandular hairs, adaxially puberulous; lobes 1.5–1.8 × 0.9–2.2 mm, apically acute, adaxially rugose. Stamens 8, 5–7.2 (–8) mm long, exserted; filaments distinct, straight, ± linear with parallel sides or broader at base, 3–4 (–5.6) mm long, abaxially and adaxially pilose, the indumentum often dense; anthers distinct, papillae on both thecae and tubules; thecae 0.9–1.5 mm long, basally appendaged; tubules 2, distinct, 1.2–2.3 mm long, dehiscing introrsely by longitudinal slits, 0.5– 1.4 mm long. Ovary 4-locular; style 5–8.5 mm long, included. Berry purple or violet, rarely reported as white in southern Ecuador (however it is possible this report comes from fruits not fully mature), ± spherical, 8–9.3 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 - Disterigma alaternoides is known from the Andes of western Venezuela, Colombia, Ecuador, Peru, and northern Bolivia. It is perhaps the most frequently collected taxon of the genus (Fig. 11). This species is abundant in the montane and premontane cloud forests but it also reaches the páramo, thus its wide altitudinal range of (1200?–) 1500–3600 m. It is been found in both primary and secondary vegetation, and roadsides and pastures with remnant vegetation. Flowering and fruiting specimens have been collected year-round.

Local Names and Uses - This species is known as "mata de caballo" (Norte de Santander), "capulí silvestre" (Nariño), "mortiño" (Antioquia, Cundinamarca), and "chite" (Cundinamarca) in Colombia; as "perlillo" (Loja), "motilón" (Bolívar), "tira" (Azuay, Loja), and "zchirpe" (Azuay) in Ecuador; as "borrachera" (Lara) and "albricias" (Mérida) in Venezuela; and as "piku-mullaca" (Amazonas) in Peru. Its fruits are eaten by both humans and birds throughout its entire distribution.

Discussion:

Disterigma alaternoides has variable leaves: (0.8–) 1.2–4(–4.7) × (0.4–)0.5–1.9(–3.5) cm, apically acute to obtuse, and with the venation well marked or completely obscure. This vegetative variability was described under different names at the species or variety level (Smith, 1933; Wilbur, 1992), but all of them share the same combination of reproductive characters (Figs. 2C, 10A,B): fascicles with usually numerous flowers; 4-merous flowers; corollas pink or white, tubular or narrowly urceolate, and characteristically puberulous inside; dense indumentum on the filaments; and white embryos. The fruits of D. alaternoides are typically purple or violet, but very few collections from southern Ecuador recorded white berries. Because it is not clear if the white berries were fully mature or not, it is not certain if the species is polymorphic in fruit color. Material from Central America was previously identified as Disterigma alaternoides (Luteyn, 1996; Wilbur, 1974, 1992) and separated from the similar D. humboldtii, which is very abundant across Central America. However, my study of these species over their entire geographic range revealed that although they are morphologically variable, D. alaternoides is confined to South America, while D. humboldtii occurs from Mexico to Peru. These findings are supported by the molecular and total evidence analyses where D. alaternoides and the OTUs of D. humboldtii were resolved in different clades (Pedraza-Peñalosa, 2009, 2010). These species can be differentiated because while D. alaternoides has flowers grouped in 3–9-flowered fascicles (sometimes combined with solitary flowers) and with the corolla puberulous within, D. humboldtii has solitary flowers (sometimes combined with 2–3-flowered fascicles) with the corolla glabrous within or nearly so; it can also be generalized that the leaves of D. alaternoides are broader overall, (0.4–)0.5–1.9(–3.5) vs. (0.3–)0.4–0.7(–1.3) cm in D. humboldtii. For morphological comparisons of D. alaternoides with other species see D. pallidum, D. ovatum, and D. verruculatum. Hybrids between Disterigma alaternoides and D. noyesiae may be present in the area of Munchique, in Cauca, Colombia, where the two populations grow sympatrically, González et al. 2941 (COL), P. Pedraza & Galindo 1154 (COL, HUA, NY), 1156 (CAUP, COL, CUVC, HUA, MO, NY), 1163 (CAUP, COL, MO, NY), 1177 (COL, NY), 1179 (COL, HUA, NY). At Munchique, some plants have long differentiated apical bracteoles (ca. 7 mm long) extending to 1.8 mm beyond the calyx and corollas completely glabrous adaxially, both characters present in D. noyesiae; otherwise, their leaves, inflorescence type, and flowers look just like any other D. alaternoides. On the other hand, the Ecuadorian specimens annotated as possible hybrids between D. alaternoides and D. cryptocalyx by Luteyn (1996), actually belong to D. noyesiae, a variable species which now is clear is not so rare.

Common Names:

mata de caballo, capulí silvestre, mortiño, chite, perlillo, motilón, tira, zchirpe, borrachera, albricias, piku-mullaca

Multimedia: