Aspidostemon trianthera

Werff, Henk Van Der, 2006, A revision of the Malagasy endemic genus Aspidostemon Rohwer & Richter (Lauraceae), Adansonia (3) 28 (1), pp. 7-44 : 41-42

27. Aspidostemon trianthera

(Kosterm.) Rohwer ( Fig. 16C )

Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 109: 75 (1987) . — Cryptocarya trianthera Kosterm. , Bulletin du Jardin botanique de l’État 27: 186 (1957). — Type: Madagascar, Mahatalaky , Fort Dauphin, [24°47’30”S, 47°05’E], 10.XII.1954, fl., Service Forestier 12064 Capuron (holo-, P; iso-, BO, TEF).

MATERIAL EXAMINED. — Madagascar. Mahatalaky , Fort Dauphin, [24°47’30”S, 47°05’E], fl., Service Forestier 10866 ( P, TEF) . — Mahatalaky , Fort Dauphin, [24°47’30”S, 47°05’E], fl., fr., Service Forestier 12064 ( P, TEF) . — Mahatalaky , Fort Dauphin, [24°47’30”S, 47°05’E], buds, fr., Service Forestier 14862 ( P, TEF) .

DESCRIPTION

Trees of unknown size. Twigs terete, glabrous; terminal glabrous. Leaves opposite, 9-15 × 3-5 cm, elliptic, glabrous, the base acute, apex acuminate, acumen 7-12 mm long, blunt, the margin flat, reticulation slightly raised on both surfaces, lateral veins 7-10 pairs but not readily visible; petioles 4-6 mm long, canaliculate. Inflorescences 2-3 cm long, paniculate, glabrous, pedicels 3-4 mm long. Flowers 2.5-3 mm in diameter, glabrous, the pedicel gradually widened towards the flower, abruptly widened at the insertion of the tepals, club-shaped, the tepals thickened and bulging outwards, giving the flower a 6-lobed appearance; stamens 3, petaloid, the locelli introrse with only the flaps visible; staminodia II and III with flattened apices, free and filling the interior of the flower; reddish curled hairs visible between the staminodia. Fruits broadly ellipsoid, smooth, 2.5 × 2 cm, the thickened tepals still visible on top of the fruits.

REMARKS

Distinctive for A. trianthera are the thickened tepals which give the flower a 6-lobed appearance, the presence of 3 tepaloid stamens with introrse locelli, and the reddish hairs in the flowers. The leaves are, for the genus, rather thin and even though the lateral veins are not very obvious, they are more readily visible than in the other species of Aspidostemon . The reddish hairs visible in the flowers are probably, as in other species, inserted at the base of the staminodia and stamens; no flowers have been dissected because the few flowers present were tightly glued to the herbarium sheet. Kostermans (1957) used a wide concept of A. trianthera . Rohwer & Richter (1987) already mentioned that Service Forestier 8512 differed from A. trianthera in its larger flowers and minute locelli; I exclude this collection also from A. trianthera . Service Forestier 8689 also differs from A. trianthera ; it has the staminodia III fused, lacks the reddish hairs in the flower and does not have the tepals as strongly thickened and bulging as A. trianthera . My concept of A. trianthera includes only 3 collections from Mahatalaky N of Fort Dauphin ( Fig. 17 ). Altitudinal data have not been mentioned on the labels.

Aspidostemon longipedicellatum can be confused with A. trianthera ; differences between the two are discussed under the former.

PHENOLOGY

Flowers and fruits: October and December.

VERNACULAR NAME

Oviary.

Figures

FIG. 16. — Species of Aspidostemon Rohwer & Richter: A, A. reticulatum Van der Werff; B, A. synandra Rohwer; C, A. trianthera (Kosterm.) Rohwer;D, A. trichandra Van der Werff. A, Service Forestier 20011, MO; B, Service Forestier 15610, P; C, Service Forestier 12064, MO; D, Ranirison 528, MO.

FIG. 17. — Distribution of Aspidostemon Rohwer & Richter in Madagascar: ■, A. reticulatum Van der Werff; ▲, A. synandra Rohwer; ▲, A. trianthera (Kosterm.) Rohwer; Ϙ, A. trichandra Van der Werff.