Homalium fortunatii Appleq., 2018

Applequist, Wendy L., 2018, A revision of the Malagasy species of Homalium sect. Blackwellia (Salicaceae), Candollea 73 (2), pp. 221-244 : 232

7. Homalium fortunatii Appleq. , spec. nova ( Fig. 2 ).

Holotypus: MADAGASCAR. Prov. Toamasina: Vatomandry , Ambalabe , along trail to Ambatobe , a deviation from Ambalabe-Sahanionaka trail , 19°18'17"S 48°37'22"E, 302 m, 4.II.2011, fl. & fr., Randrianasolo et al. 1358 ( MO-6703445! ; isotype: G!, P!; TAN) .

Homalium fortunatii Appleq. differs from H. thuarsianum (Tul.) Baill. in having minutely pubescent young twigs; elliptical to narrowly elliptical (to broadly elliptical or obovate) leaves, (3.4–)7.5–13 × (1.4–) 3.5–5.3 cm, with base convex (to rounded) and apex cuspidate with rounded tip (to rounded); and sepals and petals slightly shorter than, to slightly longer than, the calyx tube.

Tree to 12–15 m; young twigs minutely pubescent becoming glabrous. Leaves elliptical to narrowly elliptical (broadly elliptical to obovate in abnormally small leaves), (3.4–)7.5–13 × (1.4 –) 3.5 – 5.3 cm; petiole 2 – 6.5 mm; base convex (to rounded), often attenuate at extreme base; apex cuspidate with rounded tip (rounded); margins shallowly repand, with glands small, often slightly protruding; adaxial surface drying dark brown, sometimes gray-tinged, abaxial surface brown. Inflorescences paniculate, lateral, sometimes cauliflorous on small twigs, 5–11.5 cm, pubescent; flowers pedicellate with pedicels 0.7– 2 mm; bracts lanceolate to ovate, 1.8–3.5 mm (<1 mm at apex). Flowers 7–9-merous; calyx tube funnelform with rounded base, erect-pubescent; sepals ligulate (to narrowly lanceolate) with acute (to rounded) apex, 2.1–2.5 mm; petals ligulate with acute (to rounded-acute) apex, 1.8–2.7 mm; sepals and petals post-flowering pinkish white or reddish, slightly shorter than calyx tube to slightly longer, ascending, ciliate with long soft hairs, abaxial surface sparsely pubescent, adaxial surface sparsely villous; sepal glands pubescent; filaments 0.6–0.7 mm, basally villous; ovary villous; styles 4–5, 0.6–0.8 mm, basally villous.

Etymology. – Homalium fortunatii is named for botanist Fortunat Rakotoarivony; he was among the collectors of the type specimen and is a strong advocate of conservation and botanical research in the region of its collection.

Vernacular names and use. – “ Hazombatofotsy ” (Randrianasolo et al. 1358); “Vazanaomby” (Randrianasolo et al. 1358).

Wood of H. fortunatii is used for construction (Randrianasolo et al. 1358).

Distribution, ecology and conservation status. – Homalium fortunatii is known from two low-elevation humid forests in Toamasina. Because of its very small known Area of Occupancy (only 8 km ²) its conservation status may be estimated as “Vulnerable” [VU D2].

Notes. – Homalium fortunatii is among the H. thuarsianum (Tul.) Baill. group of species with paniculate inflorescences and pubescent sepal glands. Homalium thuarsianum has glabrous young twigs, usually oblanceolate to obovate (to oblongoblanceolate or elliptical leaves) with cuneate to convex bases and variable (often rounded, but rarely rounded-cuspidate) apices, and sepals and petals that are consistently longer than the calyx tube when fully developed.

Material of H. fortunatii has been misidentified as H. erianthum , which likewise has relatively large leaves and paniculate inflorescences. Homalium erianthum has glabrous sepal glands and much longer stamens, and is confined to Anstiranana.

Paratypus. – MADAGASCAR. Prov. Toamasina: Masoala Peninsula , trail just above Antalavia River on S bank , 1–2 km from coast, 15°45'S 50°02'E, 50–100 m, 19.II.1988, fl. & fr., Schatz et al. 1928 ( MO, P) .

Figures

Fig. 2. – Homalium fortunatii Appleq. A. Flowering branch; B. Flowers. [Randrianasolo et al. 1358, TAN] [Drawing: R.L. Andriamiarisoa]