Calantica sphaerocephala, Applequist, Wendy L., Phillipson, Peter B. & Schatz, George E., 2014

Applequist, Wendy L., Phillipson, Peter B. & Schatz, George E., 2014, A synoptic revision of the Malagasy endemic genus Calantica Jaub. ex Tul. (Salicaceae), Adansonia (3) 36 (1), pp. 83-102 : 100-101

10. Calantica sphaerocephala Appleq., Phillipson & G. E. Schatz, sp. nov.

( Fig. 3 )

Leaves lanceolate to narrowly elliptical; inflorescences cauliflorous; sepals bearing conspicuous glands on prominent marginal projections; stamens long (6-7.4 mm).

TYPUS. — Madagascar. Prov. Antsiranana, Anjombavola (= Ambatobiribiry) , c. 10 air-km N of Sambava, 14°10’55”S, 50°05’14”E, 280 m, 9.V.2000, fl., Lowry & Rabenantoandro 5196 (holo-, MO! ; iso-, BR!, G!, K!, P!, WAG!, TEF n.v.).

PARATYPUS. — Madagascar. Prov. Antsiranana, forest of low elevation on massif of Tsihomanaomby , 3 km NW of Seranampotaka (2 km W of Route Nationale Sambava to Vohémar), 14°06’03”S, 50°02’52”E, 150 m, 9.V.2000, post-fr., Birkinshaw et al. 734 ( G, K, MO, P).

DESCRIPTION

Tree to 8 m tall, dbh 5 cm, lower portion of trunk unbranched; bark blackish; young twigs glabrous. Leaves lanceolate to narrowly elliptical, (7-)8.5- 14.5 × 2.4-6.1 cm; petiole 5-12 mm long, glabrous; stipules caducous, awl-shaped, 0.5-1.5 mm long, glabrate; base convex; apex acute to acuminate; margins serrulate; abaxial and adaxial surfaces glabrous; venation pinnate; lateral veins weak, sometimes visible on either surface but at most slightly raised, numerous, semicraspedodromous, mostly festooned. Inflorescences cauliflorous on upper two-thirds of trunk and on branches, borne singly or clustered, 2.5-5.5(-7) cm long, many-flowered, at anthesis short-branched with flowers in dense irregularly shaped, often roughly subglobose clusters, short-pubescent with erect trichomes; bracts dark red, narrowly elliptical to oblanceolate, 1.8-3.1 mm long, with gland-bearing marginal projections, sparsely short-pubescent; pedicels 5-7.5 mm long, short-pubescent. Flowers 6-7-merous, 9-11 mm in diameter; sepals pale yellowish green, narrowly ovate to elliptical, 3.5-5 mm long, with prominent gland-bearing projections along the margin, abaxial surface short-pubescent, adaxial surface short-pubescent; sepal glands yellow to dark red, orbicular to broadly ovate, concave with sometimes prominently raised margins, 1.2-1.7 mm long, the surface almost smooth; petals pale yellowish green, narrowly oblong to narrowly oblong-elliptical, 3-4.5 mm long, slightly smaller and narrower than sepals, abaxial surface short-pubescent especially towards apex,adaxial surface short-pubescent; disk short-pubescent to glabrous; stamens 1 per petal; filaments 6-7.4 mm long, pilose; anthers reddishbrown, 0.6-0.8 mm long; ovary short-pubescent; styles 3-4, 1.8-2.2 mm long. Capsules c. 6.5 mm high, short-pubescent; seeds ovoid, c. 2.5 mm long, bearing straight white trichomes about twice as long as seed.

DISTRIBUTION AND HABITAT

Calantica sphaerocephala sp. nov. is native to a small region of northern Madagascar near Sambava; it occurs in dense, low-elevation (150-280 m) humid forest on sand or basalt.

REMARKS

Calantica sphaerocephala sp. nov. is a distinctive species, easily recognized by its cauliflorous inflorescences, which are short, usually irregularly subglobose, and dense. The sepals have prominent peg-shaped, gland-tipped marginal projections that are not present in any related species. The sepal glands are nearly smooth-surfaced and tend to be concave with elevated margins. The flowers are relatively large; the filaments are longer than those of any other species (6-7.4 mm), and the styles are unusually long (1.8-2.2 mm). The living plant is described as having horizontal branches, vertical petioles, and horizontal leaf blades (Birkinshaw et al. 734). This species does not closely resemble any other, and its affinities are uncertain.

Calantica sphaerocephala sp. nov. is native to the same part of northeastern Madagascar as Homalium cauliflorum H. Perrier , which also has cauliflorous inflorescences and similarly shaped leaves ( Perrier de la Bâthie 1940, 1946). The flowers of H. cauliflorum are 8-10-merous and less than half as large (c. 4 mm in diameter), with stamens shorter than the petals, densely hairy sepal glands, 4-6 styles, and a semi-inferior, flattened, pilose ovary.

Ethnobotany

The wood of Calantica sphaerocephala sp. nov. is said to be hard (Birkinshaw et al. 734).

Vernacular name

Piro (Birkinshaw et al. 734).

CONSERVATION STATUS

The preliminary assessment of the conservation status of Calantica sphaerocephala sp. nov. is Endangered (EN B2ab(iii)). With an Area of Occupancy of only c. 20 km 2, the species is known only from two locations, neither protected and both subject to continuing habitat degradation.

Figures

FIG. 3. — A-C, Calantica sphaerocephala Appleq., Phillipson & G. E. Schatz, sp. nov., Lowry & Rabenantoandro 5196 (holotype, MO); A, flowering branch; B, flower from above; C, flower from beneath. Drawing Barbara Alongi. Scale bars: A, 2 cm; B, C, 5 mm.