Wetschnig, Knirsch & Martínez-Azorín & Pfosser & Wetschnig, 2015

Knirsch, Walter, Martínez-Azorín, Mario, Pfosser, Martin & Wetschnig, Wolfgang, 2015, The reinstatement and rediagnosis of the madagascan genus Rhodocodon (Asparagaceae, Scilloideae), with validation and remarks on H. Perrier’s taxa, Phytotaxa 195 (2), pp. 101-134 : 122-125

10. Rhodocodon mascarenensis (Baker) Knirsch, Mart. -Azorín & Wetschnig comb. nov.

≡ Urginea mascarenensis Baker (1874: 363) ≡ Rhadamanthus mascarenensis (Baker) Speta (1998: 77) ≡ Drimia mascarenensis (Baker) Manning & Goldblatt (2004: 557) .

Illustrations:—plate VIII in Baker (1881, Fig. 1 ); fig. XVI (1) in Perrier de la Bâthie(1938: 121).

Type:— MADAGASCAR. Bojer & Hilsenberg s.n. (holotype BM 000797876!, Fig. 19 ).

= Rhodocodon madagascariensis Baker (1881: 280) . Type (lectotype, here designated):— MADAGASCAR. N & E of Ankaratra Mts, s.d., Langley Kitching s.n. (K 000099861!).

Description:—Deciduous bulbous plants, up to 30 ‒ 55 cm high. Bulb ovoid with an acute apex, 1.5 ‒ 3.3 × 1 ‒ 3 cm, splitting and forming small clumps, hypogeal, without outer tunics; roots white, branched. Leaves 2(‒ 3), absent at flowering time, appearing after the anthesis, suberect to spreading, linear, 25 ‒ 45 × 0.2 ‒ 0.3 cm, acute, bright green with smooth surface and distinctly canaliculated on the adaxial side. Inflorescence erect; peduncle thin, brownish, 20 ‒ 45 × 0.15 cm; raceme 5 ‒ 17 cm long with 5 ‒ 15 flowers; pedicels 6 ‒ 15 mm long, white, patent to nodding, upright when fruiting; bracts very small and inconspicuous, ca. 1 mm long with a spur ca. 1 mm long; bracteoles present; flowers nodding, white with a median green to red stripe on the central nerves of tepals on the apical third. Perigone campanulate to slightly urceolate, 6–7 × 5–6 mm, tepals connate for most of their length with obtuse, short, reflexed, lobes, ca. 1.2 mm long. Stamens 6, filaments shortly adnate to the perigone tube and arising from its basal portion; free portion of filaments slightly flattened, ca. 1.3 mm long, smooth; anthers almost basifixed, ca. 2 mm long, convergent over the ovary, dehiscing up to the middle or further down. Ovary ovate, ca. 2 × 2 mm, elongate, with ca. 15 ovules per locule; style ca. 2 × 0.4 mm, thinning to the top; stigma white, slightly three lobed. Capsule brown, membranous, 5 ‒ 8 × 4 ‒ 5 mm, trigonous in section, with valves splitting completely from the base to top. Seeds narrowly hemiellipsoidal, angulose, L-H-W: 3.4 ‒ 1.3 ‒ 0.8 mm, black, glossy, without a distinct raphe. Fig. 1 , 20 .

Diagnosis:— Rhodocodon mascarenensis shows a distinct morphology, that cannot be mistaken with any other Rhodocodon species due to the elongated bulbs with acute apex, the two narrow, canaliculated leaves appearing after the anthesis, the very thin peduncle, and the short raceme with 5 ‒ 15 flowers.

Habitat:— Rhodocodon mascarenensis grows between the fibrous roots of grasses and in the crevices of granite rocks, at elevations spanning 1000 ‒ 1500 m. It occurs in the Central Region characterized by a humid subtropical climate, with maximum temperatures in December (mean of 26.3°C) and minimum temperatures in July (mean of 10.2°C). The rainy season spans November to March.

Biology:—Flowering and fruiting time: November to January.

Distribution:— Madagascar. Province Antananarivo: regions Vakinankaratra and Itasy. Province Fianarantsoa: regions Amorin’i Mania, Haute Matsiatra, and Ihorombe. Province Toliara: region Anosy.

Comments:— Baker (1874) described this species as having bulbs with 6 ‒ 7 leaves, though this is due to the fact that the bulbs split easily, so that one gets the impression of a many leafed bulb. However, the illustration of Rhodocodon mascarenensis by Baker (1881) shows two inflorescences arising from one bulb, bearing 4 ‒ 5 leaves in total.

Selected material studied:— MADAGASCAR. Between Ivato and Ambatofinandrahana , February 2007, A. Sie- der & J. Andriantiana 4033 ( GZU!) ; Massif de l’Andringitra ( Iratsy ): Vallées de la Riambava et de l’Antsifotra et montagnes environnantes, pentes rocailleuses, éboulis, rochers siliceux, 2000 ‒ 2500 m, 27 November–8 December 1924, Humbert 3789 (P 02160875!) ; Madagascar , 1889, R. Baron 2165 (P 02160877!) ; Toliara, Betroka , Ivahona. Réserve Spéciale de Kalambatritra, Forêt d’Analamavo, 1320 m, 8 November 2004, R.L. Andriamiarisoa et al. 573 (P 02160878!) .

Figures

FIGURE 1. Rhodocodon mascarenensis (Baker) Knirsch, Mart.-Azorín & Wetschnig, taken from J. Linn. Soc., Bot. 18, t. 8. (1881), as Rhodocodon madagascariensis.

FIGURE 19. Holotype of Rhodocodon mascarenensis (Baker) Knirsch, Mart.-Azorín & Wetschnig: Bojer & Hilsenberg s.n. (BM 000797876!).

FIGURE 20. Flower morphology of Rhodocodon mascarenensis (Baker) Knirsch, Mart.-Azorín & Wetschnig (corresponding to WW 3431!). Lateral view (left), dissection in lateral view (center) and apical view (right). Scale bar 1 mm.