Calyptranthera villosa Klack., 2007

Klackenberg, Jens, 2007, Three new species of Calyptranthera (Apocynaceae, Secamonoideae) from Madagascar, Adansonia (3) 29 (1), pp. 113-121 : 114-116

Calyptranthera villosa Klack. , sp. nov.

( Fig. 1 )

Species haec Calyptrantherae gautieri et C. pubipetalae similis lobis corollae distincte pubescentibus autem differt lobis coronae filiformibus et adscendentibus; ab illa etiam differt antherae connectivo dorso longe piloso, a hac connectivi lobo valde filiforme prolongato.

TYPUS. — Madagascar. Province de Diego-Suarez / Antsiranana, sous-préfecture de Vohémar, commune rurale de Daraina, forêt de Binara, 13°15’S, 49°37’E, 910 m

alt., 2005, P. Ranirison & L. Nusbaumer PR 995 (holo-, S!; iso-, G, TAN).

DESCRIPTION

Suffrutescent twiner c. 1.5 m long with younger branches densely covered by more or less straight to bent often retrorse rather stiff reddish hairs, glabrescent. Leaves somewhat coriaceous, shining green above, paler below; blade 10-13 × 3-4.5 cm, narrowly obovate to elliptic, cuneate at base, acuminate at apex, with reddish bent hairs beneath, glabrescent above or with a few remaining hairs especially along the midrib towards base, without colleters at the very base above; margin entire; venation pinnate and looped, reticulate; midrib when dry distinctly impressed above and raised beneath; secondary veins divaricate to right-angled and tertiary veins grossly reticulate, slightly raised on both sides when dry; epidermis ± smooth on both sides; petiole distinct, 1-2 cm long, with dense reddish mostly appressed hairs, glabrescent. Inflorescences extra-axillary, shorter than the adjacent leaves; cyme appearing umbel-like but actually with flowers in pairs with reduced internodes at a c. 1 cm long stalk, with 7-11 flowers, hairy; pedicels 3-4 cm long; bracts and bracteols narrow, 1.5-2 mm long. Calyx lobes united only at the very base, 2-2.5 × 0.7-0.9 mm, much longer than the corolla tube, triangular, acute, with reddish hairs outside, glabrous inside, with a small colleter at each lobe sinus. Corolla ellipsoidal in bud, contorted with the left lobe margin overlying, not or only slightly twisted, with the lobes fused at the base only into a short tube, greenish white in bud turning brownish pink when mature; tube c. 0.7 mm long, glabrous; lobes c. 8 × 3.4 mm, elliptic, acute at apex, ascending to rotate, glabrous outside, villous inside but glabrous along the right margin. Staminal column c. 4.5 mm high (c. 1.5 mm with projecting connectives excluded); filaments broad with short sclerified margins (anther wings) and with five cup-like projections below (pollinium entrances), united into a short cylinder at base; anthers with connectives much prolonged into filiform appendages grouped together basally in a column but diverging above, at lower half covered with dense short and sparser much longer hairs, upper half glabrous; filiform appendages c. 3 mm long; thecae yellow. Corona lobes filiform, c. 2.5 mm long, bent outwards-upwards, shorter than the prolonged connectives, glabrous. Pollinia ellipsoidal, c. 0.15 mm long, attached to minute soft corpuscula. Style narrow and cylindric at lower half but conical below the style-head, c. 0.6 mm high; style-head c. 0.5 mm high, with a discoid lower part that abruptly narrows into the style, and with a narrower and short shallowly bilobed upper part. Fruits unknown.

HABITAT AND DISTRIBUTION

Calyptranthera villosa is known only from the type locality at Daraina in the northeastern part of Madagascar, found in dense humid forest at 910 m altitude. It was collected in flower in November .

REMARKS

Calyptranthera villosa has ascending, filiform corona lobes that are distinctly longer than the thecae. This structure is also characteristic for the large-flowered C. baronii Klack. and C. grandiflora Klack. In contrast, C. brevicaudata Klack. , C. caudiclava (Choux) Klack. , C. gautieri Klack. and C. pubipetala Klack. have short, spathulate and horizontal corona lobes. The remaining of the hitherto described species of this genus, C. schatziana Klack. from the Masoala peninsula, differs by having erect but only c. 1 mm long corona lobes, i.e. about as long as the thecae only. Although furnished with the ascending and filiform corona lobes, C. villosa is probably not closely related to C. baronii or C. grandiflora , but is with its hairy corolla lobes most similar to C. gautieri from the Manongarivo mountains c. 150 km SW of Daraina and to C. pubipetala from the Masoala peninsula c. 150 km S of Daraina, i.e. at relatively short distances from each other but phytogeographically separate. Calyptranthera pubipetala differs from C. villosa by lacking the much prolonged connectives. From C. gautieri it differs by having the corolla lobes densely and almost entirely pubescent inside with only the left margin glabrous, not half of the petal without indumentum as in C. gautieri . Furthermore C. villosa has distinctly hairy connectives, both with dense short hairs and with sparse but much longer straight hairs. See also C. sulphurea .

The epithet of this species alludes to the thick indumentum of the petal lobes.

Figures

FIG. 1. — Calyptranthera villosa Klack.: A, habit; B, flower in bud; C, flower with calyx and two petals removed; D, gynostegium with one corona lobe missing; E, anther, lateral view; F, pollinaria; G, style-head and part oF ovary. P. Ranirison & L. Nusbaumer PR 995. Drawing by Andrea Klintbjer, Stockholm. Scale bars: A, 1 cm; B, C, 5 mm; D, E, G, 1 mm; F, 0.5 mm.