Kylicanthe perezverae Descourvières, Stévart & Farminhão, 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 : 111-113

Kylicanthe perezverae Descourvières, Stévart & Farminhão , sp. nov. ( Figs. 2B , 7 )

Type:— GUINEA. Nzérékoré: Nimba Range, SMFG iron ore mine concession, station météorologique de Château, on rocky outcrops, 7°40’33.00”N 8°22’45.00”W, 6 August 2012, Nimba shadehouse series 213 (holotype: BRLU!).

Kylicanthe perezverae is similar to K.rohrii but differs in its laxer inflorescence, suborbicular dorsal sepal, inconspicuous lip callus, a narrowly conical spur and an emarginate lip apex.

Epiphytic herbs. Roots basal on the stem, unbranched, greyish. Stem with a few leaves in a fan, 20–40 mm. Leaves oblong to elliptic, suborbicular, margins entire, apex unequally bilobed with or without a 1 mm notch, lobes acute, 13–90 × 6–15 mm. Inflorescences pendent, wiry, emerging at the base of the stem, 1–7-flowered, 20–115 mm long, floral internodes about 4–16 mm, rachis terete; bracts amplexicaul, 1.5–2.0 mm long. Flowers resupinate, whitish to yellowish green, 9–11 mm in diameter; dorsal sepal elliptic suborbicular, apex obtuse, margins entire, triveined, 3.0– 5.5 × 2.5–3.0 mm; lateral sepals elliptic, slightly keeled dorsally, apex obtuse to subacute, margins entire, triveined, 3.5–5.5 × 2.0 mm; angle between dorsal and lateral sepals about 120°; petals elliptic to lanceolate, apex obtuse, margins entire, triveined, 3.0–5.5 × 1.6–1.8 mm; lip broadly ovate, entire, margins entire, lateral margins not or slightly deflexed, 5-veined, with a callus, apex emarginate, 3.0–4.5 × 3.0– 3.3 mm; lip callus an inconspicuous tooth in the mouth of the spur; spur narrowly conical, somewhat laterally flattened, mouth slightly spreading, rectilinear or slightly curved, apex rounded, angle formed by the ovary and the proximal part of the spur 20–45°, 10.0– 13.5 mm long; ovary and pedicel 5 × 1 mm. Column 1.5–2.0 × 2.2–2.5 mm; anther cavity approximately perpendicular to the axis of the column; stigmatic cavity cup-shaped, margins large and winged, 3 veins; rostellum triangular and bifid, about 1 mm long; pollinia 2, spherical; stipes 2, separate along their length, spatulate, with inner and outer margins subequal, erose, 1.0– 1.2 mm long, connected to a single calceiform viscidium. Fruits ventricose, pedicellate.

Distribution: —Known only from the Nimba Range ( Guinea) and Monts des Dan ( Ivory Coast), where it is probably endemic, 800–1,300 m ( Fig. 3 ).

Habitat and ecology: —Epiphytic on shrubs, treelets and trees. In the Nimba Range, it was found in shrubby vegetation isolated in savannah, but also in forests, where it grows on high branches and on small trees on rocky outcrops. This heliophilic species grows on small twigs or on large branches, sometimes forming large populations (often more than 20 individuals).

Phenology: —Flowering June–July.

Conservation status: —The IUCN Red List category is endangered [EN]. The extent of occurrence (EOO) of K. perezverae is estimated to be 265 km 2, which falls within the limits for endangered category under criterion B1, and its area of occupancy (AOO) is estimated at about 16 km 2, which is within the limits for endangered category, likewise under criterion B2. This species is restricted to the remaining forest and woodland of isolated mountain ranges in Guinea and Ivory Coast, and its distribution is thus extremely fragmented. Kylicanthe perezverae is known from two subpopulations, one of which is partly encompassed within legally protected areas (the Nimba Mountains World Heritage Site). These two subpopulations thus represent a total of three locations, below the threshold for endangered category under criterion B2. Since the species is resistant to the frequent human-caused fires that regularly affect the sites where it occurs, the main threat it may face is habitat destruction due to road construction associated with the on-going exploration phase of mining projects at Nimba. Moreover, a decision to proceed with the planned mining activities would significantly increase the scope and intensity of impacts, thereby resulting in a higher level of threat. Although a decision to begin exploitation is currently on hold, such a project will result in loss of its habitat, which leads us to predict a continuous decline in the quality of its habitat, as well as of the number of subpopulations and mature individuals, and thus, also of its AOO. Kylicanthe perezverae is therefore assigned a preliminary status of EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).

Etymology: —The species epithet honours Francisco Pérez-Vera, a medical doctor by training, who contributed significantly to the orchid flora of Ivory Coast. Pérez-Vera was the first to collect this species, and a detailed description, a drawing and photographs of K. perezverae feature in his book on the orchids of Ivory Coast ( Pérez-Vera, 2003), which is a definitive reference to the study of the Orchidaceae of the Upper Guinean forests.

Notes: —This new species is depicted in Pérez-Vera (2003 p. 270, 281), under the name of Diaphananthe quintasii , with three pictures (flowers and plant in cultivation at Bouaké) and a description and a drawing. The slightly conical spur and the emarginate lip apex are easily observable on pictures and drawing, these features being diagnostic of this species. The only gathering from Ivory Coast that we were able to locate (Pérez-Vera 1123/b) is now housed at the herbarium of the University of Granada (GDA), to which F. Pérez-Vera bequeathed his personal collection ( Baena et al. 2008). Pérez-Vera (2003) cited this species from Mont Momi in Ivory Coast, but the associated specimen (Pérez-Vera 815) was not located at GDA.

Additional specimens examined: — GUINEA. Nzérékoré: Nimba Range , SMFG iron ore mine concession, station métérologique de Château, on rocky outcrops, 7°40’33”N 8°22’45”W, 6 August 2012, Nimba shadehouse series 212 (BRLU) ; ibid. loc., 5 October 2011, Stévart, Bidault, Diabaté & Bilivogui 4064 (BRLU) ; Nimba, Seringbara, Camp 2, Nimba plot 7, 1,166 m, 07°37’45”N 008°25’08”W, 14 September 2017, Stévart et al. 5049 (BRLU, MO, SERG) ; Nimba, summit of Leae mountain , 843 m, 07°39’13”N 008°20’46”W, 22 September 2017, Stévart et al. 5077 (BRLU, MO, P, SERG) . IVORY COAST. Montagnes: Mont Tonkoui, en culture à Bouaké , 16 August 1996, Pérez-Vera 1123/b (GDA) .

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.

FIGURE 7. Kylicanthe perezverae. A. Habit. B. Inflorescence. C. Flower. D. Dorsal sepal. E. Lateral sepal. F. Petals. G. Lip in dorsal view. H. Floral pedicel, ovary and column. I. Anther cap in posterior view. J. Column in frontal view showing rostellum. K.Anther cap in frontal view. L. Anther cap in ventral view with one pollinium still inside. M. Pollinaria with pollinia in lateral view. Drawn by Hans de Vries after Nimba shadehouse series 212 & 213.