Bolusiella fractiflexa Droissart, Stévart & Verlynde, Phytotaxa 114: 7 (2013).
Description:
Epiphytic herb with non-branching stem, 4–5 mm and 1 mm internodes. Leaves not deeply sulcate on upper surface, 15–20 × 4–5 mm, pointed at apex. Inflorescences 28–36 mm long, with a fractiflex base, 6–9 flowered, clustered at apex (10 mm long). Floral bract black, triangular, larger than flowers, 4.0–5.0 × 2.4–2.8 mm with an acuminate apex, sheathing, imbricate in the sterile portion of the inflorescence. Flowers 2.5–3.2 mm long, 1–2 mm diameter, 1 mm apart from each other. Dorsal sepal triangular, 1.8–2.8 × 0.9–1.0 mm. Lateral sepals triangular, 1.9–2.4 × 0.7–1.2 mm, carinate, with a basal pouch-like outgrowth. Petals triangular, 1.3–2.0 × 1.0 mm. Lip broadly triangular, 1.1–1.8 × 1.0–1.2 mm. Spur conical, short, 1.1 mm long, 0.6 mm diameter or almost absent in the Cameroon specimens. Column 0.4–0.8 mm long. Ovary 1.0–1.6 mm long and 0.5–0.8 mm in diameter.
Etymology:
The specific epithet refers to the shape of the basal part of the inflorescence that represents a diagnostic character of the species.
Habitat:
In Cameroon, living specimens were collected on fallen branches of 8–10 cm diameter, in lowland semi-deciduous forests under partial cultivation (banana and cocoa plantations). In Rwanda, the species was collected in montane forest with Parinari excelsa Sabine (1824: 451) and Syzygium guineense (Willd.) de Candolle (1828: 259). Flowering peak in September.
Cultivation:
As given for the genus.
Notes:
This species is morphologically similar to Bolusiella maudiae and Bolusiella talbotii (Rendle, 1913: 108) Summerh. in Hutchinson & Dalziel (1936: 456) in its floral and vegetative features. It differs from Bolusiella maudiae in the shape of its leaves, which do not have a rounded apex, and it differs from Bolusiella talbotii in its fleshier leaves. In addition, the sinuate shape of the basal part of the inflorescence and reduced or absent spur easily distinguish it from both other species.
Distribution:
Lower Guinea Domain and Afromontane Region (Kivu-Ruwenzori regional mountain system): Cameroon, Burundi and Rwanda.
References:
WCSP (2017). 'World Checklist of Selected Plant Families. 19.02-2017; http://apps.kew.org/wcsp/
Images:
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