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 staphelioides (Planch. ex Wedd.) Nied.

Synonyms:

Vaccinium staphelioides Planch. ex Wedd., Disterigma cuspidatum (Planch. ex Wedd.) Nied., Vaccinium cuspidatum Planch. ex Wedd.

Description:

Species Description - Terrestrial shrubs, scandent, prostrate and decumbent, or erect, 0.5–3 m tall. Young branchlets not ridged, ± smooth, villous, the hairs eglandular and often wavy, the indumentum of the mature branches similar but villous or glabrate. Leaves 9–14 per cm, apparently distichous, patent to reclinate; petiole 0.5–1.6 mm long, glabrate or puberulous, the hairs eglandular; lamina slightly succulent, ovate, (0.5–)0.6–0.8(–1) × (0.2–)0.4–0.5 cm, basally cordate or obtuse, marginally entire or rarely inconspicuously crenulate towards apex, apically ciliolate with eglandular hairs, apically sharply acuminate, long-acuminate, or rarely acute, adaxially glabrous or glabrate with eglandular hairs, abaxially glabrate with glandular hairs, the venation adaxially obscure, abaxially hyphodromous or 3-nerved with the midvein raised. Axillary solitary flowers; bracts 4–5, chartaceous, ovate or transverse-elliptic, 2–3.2 × 1.6–3.6 mm, marginally ciliate with eglandular hairs, apically obtuse and cuspidate, abaxially glabrous; pedicel 1.2 mm long, reduced and hidden by overlapping bracts, minutely villosulous with eglandular hairs; differentiated apical bracteoles 2, distinct, chartaceous, enveloping to part of calyx lobes, covering 63–87% of calyx, ovate, 3.2–5.6 × 3.2–4 mm, marginally ciliate with eglandular hairs, apically obtuse and cuspidate or acuminate, the surface smooth, abaxially and adaxially glabrous. Flowers 4-merous. Calyx aestivation valvate, campanulate, (5–)5.6–7.1 mm long; tube terete, (1.3–) 1.6–2 mm long, abaxially glabrous; limb (3–)3.6–5.3 mm long, abaxially and adaxially glabrous; lobes triangular, (2.8–)3.6–5.2 × (1–)1.2–1.6 mm, marginally ciliate or ciliolate with eglandular hairs, apically acuminate or long-acuminate; sinuses rounded (U-shaped). Corolla white, thin-fleshy, bistratose, urceolate (inflated at the middle), (5–)7–9.5 mm long, 2.4–3.6 mm diam., 1.6–2.4 mm wide at throat, abaxially glabrate with eglandular hairs, adaxially glabrous; lobes (1.2–)2–2.8 × (0.8–)1.2–1.6 mm, apically acute, adaxially rugose (at least on the margins or apex). Stamens 8, (5.5–) 7.1–7.6 mm long, exserted; filaments distinct, straight, broader at base, 3.5–4 mm long, abaxially and adaxially pilose; anthers distinct, papillae only on thecae; thecae 1–1.6 mm long, without basal appendages; tubules 2, distinct, (1.4–)2–2.4 mm long, dehiscing introrsely by longitudinal slits, 2 mm long. Ovary 4- locular; style (5.5–)6.5–7.9 mm long, exserted; nectary rarely with few hairs. Berry purple, ± spherical, 5.2 mm diam. (immature), the persistent calyx lobes erect or spreading, becoming succulent (at least at base), same color as mature berry; embryo white.

Distribution and Ecology - Disterigma staphelioides is widespread in the northern Andes where it is found in the three Colombian cordilleras as far south as Nariño; it is also found in the east in Monte Roraima at the border of Brazil, Guyana, and Venezuela (Fig. 43). This species grows at 1500–3500 m in the montane and premontane cloud forest, as well as in the subpáramos and páramos. It has been recorded growing in both primary and secondary vegetation as well as on roadsides. Flowering year-round; fruiting in Mar, and May–Aug.

Discussion:

The study of specimens of Disterigma staphelioides and D. cuspidatum revealed that there is no clear-cut distinction between them using the characters proposed by Smith (1933). Although the apical bracteoles of D. cuspidatum are distinctively long-acuminate and mostly obtuse to subacute, acute bracteoles are also found in flowers of D. staphelioides, including some from the type specimens. The apex of the differentiated apical bracteoles is not considered to be significant enough to grant species distinction, and the other suggested diagnostic characters that would be more significant at the specific level, e.g., corolla dimension, occur with either obtuse or acuminate bracteoles. The basonyms of both names, Vaccinium staphelioides and V. cuspidatum, were published on the same page of Chloris Andina by Weddell, using a name provided by Planchon in an unpublished manuscript. Vaccinium staphelioides is here regarded as the most appropriate basionym for the species because the original description is not only detailed, but it also explicitly identifies a type collection. On the other hand, the description of V. cuspidatum is very brief and consists of only two nonspecific characters shared by many other Ericaceae. Disterigma staphelioides (Fig. 42A) is distinguished by numerous, apparently distichous, small, ovate leaves, usually with apices acuminate and pricking; long (almost as long as the limb), narrow, and acuminate calyx lobes; rounded calyx sinuses; urceolate and adaxially glabrous corollas; and purple berries with white embryos. Vegetatively, D. staphelioides is similar to D. acuminatum and D. dendrophilum, but it can be differentiated from the others because its calyces are 5 mm or more long (vs. to 3.6 mm long in the other species), calyx lobes are more than 3 mm long (vs. to 2 mm long), sinuses are rounded (vs. acute), corollas are (5–)7–9.5 mm long (vs. to 6 mm long), and stamens are at least 5.5 mm long (vs. to 5 mm long). I consider that Callejas & Roldán 10590 (HUA, NY) from Colombia (Antioquia), and Maguire 33324 (NY, US), Steyermark & Wurdack 1156 (F, NY, US), and Steyermark 58713 (A, F) from Venezuela (Chimantá and Roraima), could be of hybrid origin, resulting from crosses between D. staphelioides and D. humboldtii. These specimens fall outside of the expected variation; their leaves are ovate to elliptic, with an apex acute, blunt-acute, or subacute, and their margin crenulate or entire; their calyx lobes are shorter than average, just 2–3 mm long; and their corollas are adaxially puberulous or glabrous. Populations from both paternal species co-exist in the area where these unusual specimens were collected; additional fieldwork in these regions would be useful, allowing detailed molecular and morphological studies to be conducted.