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 stereophyllum (A.C.Sm.) Luteyn

Synonyms:

Killipiella stereophylla

Description:

Species Description - Epiphytic or terrestrial shrubs, scandent. Young branchlets ridged, ± smooth, mostly glabrate or puberulous, the hairs inconspicuous, eglandular, white, the mature branches glabrous. Leaves 3–6 per cm, spirally arranged, diffuse or patent; petiole 1–3 mm long, glabrate, the hairs inconspicuous, eglandular; lamina elliptic, oblanceolate, or rarely ovate, 0.9–2.9 × 0.3–1.3 cm, basally obtuse or truncate, marginally entire, apically ciliolate with eglandular hairs, apically acute, adaxially glabrous or the young leaves glabrate with inconspicuous eglandular hairs over the midvein, abaxially glabrate with minute glandular hairs, the venation adaxially hyphodromous with the midvein impressed, abaxially hyphodromous or 3-nerved with the midvein raised. Axillary and subterminal solitary flowers; bracts 7–9, chartaceous, ovate or elliptic, 0.8– 3.4 × 1–3 mm, occasionally marginally ciliate with eglandular hairs, apically obtuse, abaxially glabrous or rarely glabrate with inconspicuous eglandular hairs; pedicel 0.8–1.5(–2.5) mm long, reduced and hidden by overlapping bracts, glabrate with minute glandular hairs; differentiated apical bracteoles 2, distinct, chartaceous, enveloping to lower half of calyx lobes, covering 58–76% of calyx, ovate, elliptic, or suborbicular, (3–)4.4–6 × (3–)4.4–6 mm, marginally ciliolate with minute eglandular hairs, apically obtuse, the surface softly longitudinally striate (appears smooth in most of the liquid-preserved material), abaxially glabrous or sometimes glabrate with inconspicuous eglandular and glandular hairs, adaxially glabrous. Flowers 4-merous. Calyx aestivation imbricate, campanulate, (5–)5.5–8.7 mm long; tube slightly angled, 1.2–2 mm long, abaxially glabrate with minute glandular hairs; limb (3.8–) 4.3–7.1 mm long, abaxially glabrate with inconspicuous eglandular and glandular hairs, adaxially glabrous; lobes elliptic (triangular in only a few flowers from Ansermanuevo, in Valle del Cauca, Colombia), (3.5–)4–5.3(–6.5) × (1.2–)2.2–3.5(–4.4) mm, marginally ciliolate with eglandular hairs, apically obtuse and apiculate or very rarely subacute and apiculate; sinuses obscured by the overlapping bases of the imbricate lobes (the lobes spread when the calyx lobes are triangular). Corolla pink or white, thick-fleshy, not bistratose, urceolate (inflated in the middle), (6–) 7.5–10(–11.5) mm long, 4–4.4 mm diam., 1.5–2 mm wide at throat, abaxially glabrous or glabrate with glandular hairs, adaxially glabrate; lobes 1–1.6 × 1– 1.5 mm, apically acute, adaxially rugose. Stamens 8, (5.6–)7–8(–8.2) mm long, included; filaments distinct, straight, obtriangular, (3.3–)3.6–5 mm long, abaxially glabrous or rarely glabrate with inconspicuous hairs, adaxially pubescent; anthers distinct but tightly packed, papillae only on thecae; thecae 1.3–1.9(–2.2) mm long, without basal appendages; tubules 2, distinct, (2–)2.2– 2.6(–3.1) mm long, dehiscing introrsely by longitudinal slits, 0.9–1.5(–1.7) mm long. Ovary 4-locular; style 7.6–8.8 mm long, exserted. Berry white, ± spherical, 6.5–7.5 mm diam., the persistent calyx lobes converging and overlapping, green; embryo white.

Distribution and Ecology - Disterigma stereophyllum is found in the northwestern Andes from Chocó, Colombia, to Carchi, Ecuador (Fig. 38). This rare species grows at 750–2100(–3000) m in the montane and premontane cloud forest as well as in the transitional zone to the lowland rainforest. It has been recorded growing in both primary and secondary vegetation as well as on roadsides and pastureland with remnant vegetation. Flowering year-round; fruiting in Dec–Feb and Jul–Aug.

Local Names and Uses - This species is known as "chaquilulo" in Nariño, Colombia.

Discussion:

Disterigma stereophyllum (Figs. 2F, 44A) is easily diagnosed by the axillary and subterminal solitary flowers; differentiated apical bracteoles, which envelope up to the lower half of the calyx lobes, and which are moderately striate; imbricate calyx aestivation with the calyx sinuses obscured by the overlapping bases of the imbricate lobes; elliptic, long, apically apiculate, and obtuse or subacute calyx lobes; obtriangular filaments; white fruits crowned at maturity by the converging and overlapping green calyx lobes (Fig. 44B); and white embryos. Although more or less characteristic, the leaves of this species vary greatly in size, even within the same plant. Often, the leaves of the young branches of the current growing season are half the size of the regular leaves. Another variation is that of the calyces of some of the specimens from the vic. Ansermanuevo, Valle del Cauca, Colombia (Luteyn et al. 7299, 7310; Díaz-P. 3577): the calyx lobes of some flowers are more triangular than elliptic and consequently not wide enough to cause their bases to become strongly imbricate and obscure the calyx sinuses at anthesis (although the aestivation remains imbricate). Perhaps this feature has been fixed in some individuals with the help of the apparently low population density observed for this species. For a discussion of the morphological similarities of this species with others see Table XI under D. pseudokillipiella.

Common Names:

chaquilulo

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