Disterigma ovatum (Rusby) S.F.Blake
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Authority
Pedraza-Peñalosa, Paola. 2010.
(Ericaceae, Vaccinieae). Fl. Neotrop. Monogr. 108: 1-126. (Published by NYBG Press) -
Family
Ericaceae
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Scientific Name
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Type
Type. Bolivia. La Paz: Zongo [sheets marked M. Bang 876 read either Cochabamba: vic. Cochabamba and 1891, or, Songo and 1890 or 1891], 1891 (fl), M. Bang 876 (holotype, NY; isotypes, C n.v., COL, E, F n.v., G-2 sheets, GH n.v. sheet not found, K n.v. sheet not found, LPB, MICH, US-2 sheets).
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Etymology
The species name ovatum refers to the ovate shape of some leaves.
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Synonyms
Vacciniopsis ovata Rusby
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Description
Species Description - Epiphytic or terrestrial shrubs, scandent or erect, to 3 m tall. Young branchlets usually with a mucilaginous exudate distally, ridged, ± smooth, puberulous or glabrate, the hairs eglandular, white, the indumentum of the mature branches similar. Leaves 0–4 per cm, spirally arranged, diffuse; petiole 2–3.5 mm long, glabrate or puberulous, the hairs eglandular; lamina elliptic, or less often obovate or ovate, 1.2–2.4(–3.5) × 0.6–1.2 (–1.9) cm, basally obtuse or cuneate, marginally entire, slightly revolute toward base, apically ciliolate with eglandular hairs (especially in young leaves), apically obtuse and usually prominently apiculate, adaxially glabrous or glabrate in young leaves with eglandular or glandular hairs, abaxially glabrate with glandular hairs, the venation hyphodromous on both sides, the midvein adaxially impressed and abaxially raised. Axillary solitary flowers and rarely in 2(–3)-flowered fascicles; bracts 4–6, chartaceous, ovate, 0.8–2.4 × 0.9–2.8 mm, marginally eciliate, apically obtuse, abaxially glabrous; pedicel 0.9–1.5 mm long, reduced and hidden by overlapping bracts, glabrous or glabrate with glandular hairs; differentiated apical bracteoles green, 2, distinct, chartaceous, enveloping the base of the calyx tube or the entire calyx tube, covering 40–60% of calyx, ovate or elliptic, 2–3.5 × 2.3–3.9 mm, occasionally marginally ciliolate with minute eglandular hairs (apically), apically obtuse, the surface smooth and keeled, abaxially and adaxially glabrous. Flowers 5-merous, rarely corollas 4- or 6-lobed, or calyces appearing 4-lobed because the fifth lobe is reduced or because two adjacent lobes are much smaller and closer. Calyx aestivation valvate, campanulate, (3.8–)4.5–5.3(–5.7) mm long; tube terete, (1.8–)2–2.5(–2.7) mm long, abaxially glabrate with glandular hairs; limb (2–)2.5–3.2 mm long, abaxially glabrous or glabrate with eglandular hairs, adaxially glabrous; lobes triangular, 1.5–2(–2.5) × 1.4–1.7 mm, sometimes ciliolate with eglandular hairs, apically acute; sinuses acute (V-shaped). Corolla pink or white, thick-fleshy, bistratose, urceolate, (5.6–) 6.5–7.5(–9) mm long, 3.7–6 mm diam., 2.3–4 mm wide at throat, abaxially glabrate with glandular hairs, adaxially glabrate, rarely even on the lobes; lobes (1.1–) 1.5–2 × 1.2–1.5 mm, apically acute, adaxially rugose. Stamens 10, (4.8–)5.5–6.7 mm long, included; filaments distinct, straight, ± linear with parallel sides, (2.5–)2.7–3.5 mm long, abaxially and adaxially puberulous distally; anthers distinct, papillae only on thecae, at times with a couple of long hairs at base; thecae 1.3–1.8 mm long, basal appendages present or not; tubules 2, distinct, 1.6–2.1(–2.6) mm long, dehiscing introrsely by longitudinal slits, 0.8–1.1 mm long. Ovary 5-locular; style 6.8–7.8 mm long, exserted. Berry violet to almost black,± spherical, 6–7 mm diam., the persistent calyx lobes erect or spreading, becoming succulent (at least at base), same color as mature berry; embryo green.
Distribution and Ecology - Disterigma ovatum is found in the central Andes, more specifically in Cusco, Huánuco, and Pasco, Peru, as well as in Cochabamba and La Paz, Bolivia (Fig. 35). This plant grows in cloud forests at (1800–)2000–3500(–3800) m. It is locally abundant and has been recorded in both primary and secondary vegetation, as well as on roadsides and pasture lands with remnant forest. Flowering in Jan, Mar–May, Jul, Sep, and Oct; fruiting in Apr–Jun and Aug–Oct. Bumblebees have been seen visiting its flowers (P. Pedraza et al. 1503, 1505, 1516).
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Discussion
Although the epithet of Disterigma ovatum refers to its ovate leaves, elliptic leaves are more common throughout its distributional range. This species (Fig. 34C) can be differentiated from the rest of the genus by having leaves apically obtuse and usually prominently apiculate, with their margins becoming slightly revolute toward the base after drying; flowers mostly 5-merous, but rarely appearing 4-lobed because one of the calyx lobes is very small or because two adjacent lobes are so shifted, one next to the other, that they give the impression of being one lobe; corolla pink or white, thick-fleshy, urceolate, and adaxially glabrate; and berries violet to almost black, with green embryos. The type collection diverges from the usual D. ovatum in having smaller flowers and corollas with hairs even on the lobes. The overall morphology of Disterigma ovatum recalls that of D. ollacheum; their major differences are presented in Table X. Smith (1933) considered D. ovatum to be related to D. alaternoides, but they differ from each other in many ways; for example, D. ovatum has 5-merous flowers and green embryos, while D. alaternoides has 4-merous flowers and white embryos.
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Objects
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Distribution
Peru South America| Cusco Peru South America| Huánuco Peru South America| Puno Peru South America| Bolivia South America| Cochabamba Bolivia South America| La Paz Bolivia South America|