Kylicanthe Descourvières, Stévart & Droissart, 2018

Descourvières, Pascal, Farminhão, João N. M., Dubuisson, Vincent Droissart Jean-Yves, Simo-Droissart, Murielle & Stévart, Tariq, 2018, A new genus of angraecoid orchids (Orchidaceae: Angraecinae) with highly distinctive pollinaria morphology, including three new species from tropical West and Central Africa, Phytotaxa 373 (2), pp. 99-120 : 101-103

Kylicanthe Descourvières, Stévart & Droissart , gen. nov. ( Fig. 2 )

Type: Angraecum bueae Schlechter (1906: 159) .

The new genus is most similar morphologically to Diaphananthe (including Chamaeangis ) in the structure of the rostellum and pollinarium but differs in the large and cup-shaped stigmatic cavity with large margins more or less winged; the pollinarium consists of a single calceiform viscidium and 1 or 2 stipes with fringed margins; it has distinctive ventricose fruits.

Epiphytic perennial herbs. Roots at the base of the stem, 2–6 mm in diameter. Stem with a few leaves in a fan, up to 60 mm long. Leaves imbricate, distichous, generally no more than ten, slightly conduplicate, oblong, linear to obovate, sometimes slightly falcate, with entire margins, bilobed at apex, generally unequally bilobed, 13–160 × 6–27 mm. Inflorescences emerging at the base of the stem, 1–20-flowered, nodes single-flowered, up to 300 mm long; bracts amplexicaul, 1–6 mm long. Flowers white or green, greenish, yellow, yellowish, beige, resupinate or non-resupinate, 6–15 mm in diameter; sepals, petals and labellum free; dorsal sepal entire, elliptic or lanceolate, or suborbicular to orbicular, margins entire, 3.0–8.6 × 1.2–4.1 mm; lateral sepals entire, elliptic to linear, sometimes lanceolate, margins entire, 3.2–8.1 × 1.0– 3.7 mm; petals elliptic to linear, sometimes lanceolate, margins entire, erose to slightly fringed, 2.8–8.0 × 1.0– 2.8 mm; lip entire, elliptic, cordate or triangular, margins entire or erose, with an inconspicuous callus, 2.5–8.7 × 1.5–5.0 mm; spur always present, 5–24 mm long; ovary and pedicel 4.0–9.0 × 0.7–1.5 mm. Column 1.0– 5.0 × 1.0– 3.5 mm; stigmatic cavity cup-shaped, margins more or less winged, 3 veins generally visible; rostellum triangular and bifid; pollinia 2, spherical; stipes 2 spatulate, completely separate or more or less connate along their inner margins, or 1 obcordate, margins clearly erose to fringed, 0.8–1.6 mm long, connected to a single calceiform or pisiform viscidium. Fruits ventricose, shortly pedicellate.

Distribution: —Tropical Africa, 100–3,000 m ( Fig. 3 ).

Etymology: —The genus name comes from the ancient Greek ‘ kylix ’, a type of wine-drinking cup with a broad and relatively shallow body, and from ‘ anthos ’ meaning flower, for the broad cup-shaped stigmatic cavity of the flower. The ending ‘ anthe ’ also alludes to Diaphananthe , the genus in which formerly some of the species were included.

Notes: —The overall structure of the column of Kylicanthe , characterised by a deeply concave stigmatic cavity with winged margins, also resembles those of Aerangis and Eurychone , and accordingly the key characters to differentiate Kylicanthe from the former two genera are presented below.

Figures

FIGURE 2. Overview of Kylicanthe diversity. A. Kylicanthe arcuata, plants growing as twig epiphytes in Mt. Etindé (Cameroon) and detail of the flowers. B. Kylicanthe perezverae, seed capsules of a plant grown at the Nimba shadehouse (Guinea). C. Kylicanthe liae, habit and detail of a flower showing a prominent orange viscidium, in cultivation at Huye orchid garden of the University of Koblenz- Landau guest house (Rwanda). D. Kylicanthe bueae, habit of a plant grown at Yaoundé shadehouse (Cameroon) and detail of a flower. E. Kylicanthe quintasii, detail of inflorescence of a plant from São Tomé Island. F. Kylicanthe rohrii, detail of inflorescence of a plant from Tanzania. G. Kylicanthe cornuata, detail of flowers of a plant grown at Yaoundé shadehouse (Cameroon). Photographs by: A., D. and G. Vincent Droissart; B. Ehoarn Bidault; C. Eberhard Fischer; E. Tariq Stévart; F. W. Bachmann, facilitated by the World Orchid Iconography of the Swiss Orchid Foundation at the Herbarium Jany Renz (Botanical Institute, University of Basel, Switzerland).

FIGURE 3. Distribution of the seven species of Kylicanthe in tropical Africa.