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 : 120

8. Rhodocodon intermedius [H.Perrier ex] Knirsch, Mart.-Azorín & Wetschnig sp. nov.

≡ Rhodocodon intermedius Perrier de la Bâthie (1938: 116) , nom. inval.

Type:— MADAGASCAR: Plaine sèche-alluvionnaire, sur la rive droite de la Mananjeba (Andavakoera), July 1963, Perrier 10965 (holotype P 00573461!, Fig. 16 ; isotype P 00573462!) .

Description:—Deciduous bulbous plant, 10 ‒ 28 cm high. Bulb ovoid, 3 ‒ 4 × 2 ‒ 3 cm, not proliferous; roots white, branching. Leaves 5 ‒ 7 per bulb, absent at flowering time, linear, acute, 8 ‒ 22 × 0.4 ‒ 0.8 cm, appearing after anthesis, green, entire, glabrous, smooth, with a keel on the abaxial side. Inflorescence an erect, lax raceme; peduncle purple, 5 ‒ 12 cm long, glabrous, smooth; raceme 4 ‒ 12 cm long with 9 ‒ 30 flowers; pedicels purple, 5 ‒ 20 mm long at anthesis, up to 25 mm long in fruit, suberect to patent; lowermost bracts lanceolate, ca. 2 mm long, with an oblong spur ca. 1.5 mm long; bracteoles present; flowers nodding, white with a greenish narrow central band on each tepal on the upper third. Perigone campanulate to slightly urceolate, 4 ‒ 6 × 4 ‒ 5 mm, tepals connate for most of their length, with triangular, patent to 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 converging over the ovary, linear, smooth, very short, ca. 0.3 ‒ 0.5 mm long; anthers sagittate, ca. 1.3 mm long, with an acute, long apex, attached to the filaments at the inferior quarter, with joining and equal anther sacs. Ovary subglobose to cylindrical, 1.8 ‒ 2 × 1.5 ‒ 1.8 mm with 2 ‒ 4 ovules per locule; style 2.7 ‒ 3 mm long. Capsule subspherical, ca. 5 × 5 mm, often with a single seed per locule. Seeds fusiform, L-H-W: 3 ‒ 1.9 ‒ 1.8 mm, black, slightly glossy, with a black distinct raphe. Fig. 17 .

Diagnosis:— Rhodocodon intermedius is unique within the genus by having white, subcampanulate flowers with very short filaments, sagittate and long acute anthers and fusiform seeds with a distinct black raphe; the latter character is only shared with R. graciliscapus .

Habitat:— Rhodocodon intermedius grows in alluvial, gravel habitats near Ambilobe, between 50 ‒ 100 m elevation. The climate has a tropical monsoonal character, with the highest temperatures in November (mean temperature 28.2°C) and the lowest in July (mean temperature 24.4°C). The highest precipitations occur in January (mean of 473 mm) and the lowest in July (mean of 12 mm).

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

Distribution:— Madagascar, Province Antsiranana, region Diana, east of Ambilobe, north of the road to Daraina.

Comments:—Perrier de la Bâthie states that Rhodocodon intermedius resembles R. linearifolius but according to our data the former has 5 ‒ 7 leaves per bulb, 15 ‒ 29 × 0.5 ‒ 0.8 cm which cannot be mistaken with the rigid, narrower leaves of R. linearifolius .

Selected material studied:— MADAGASCAR. Province Antsiranana, region Diana, E of Ambilobe, N of the road to Daraina, February 2007, W. Knirsch, A. Sieder & J. Andriantiana 3974 (GZU!).

Figures

FIGURE 16. Holotype of Rhodocodon intermedius H.Perrier ex Knirsch, Mart.-Azorín & Wetschnig: Perrier 10965 (P 00573461!).

FIGURE 17. Flower morphology of Rhodocodon intermedius H.Perrier ex Knirsch, Mart.-Azorín & Wetschnig (corresponding to WW 4474!). Lateral view (left), dissection in lateral view (center) and apical view (right). Scale bar 1 mm.