Homalium ciliolatum (Sleumer) Wassel & Appleq.

Wassel, Anna C. & Applequist, Wendy L., 2020, A revision of Homalium sect. Nisa (Salicaceae) endemic to Madagascar, Candollea 75 (1), pp. 1-23 : 5-6

2. Homalium ciliolatum (Sleumer) Wassel & Appleq. , comb. & stat. nov.

≡ Homalium nudiflorum var. ciliolatum Sleumer in Bull. Jard. Bot. Belg. 43: 299. 1973.

Lectotypus (designated here): MADAGASCAR. Reg. Vatovavy-Fitovinany [Prov. Fianarantsoa]: Ifanadiana, forêt d’Ambohimiera [Tsaratanana], 20.VIII.1954, fl., fr., Service Forestier 14566 ( P [ P00375093 ]!; isolecto-: L [ L0010977 ] image seen, P [ P04734282 ]!) .

Tree to 25 m tall, 1 m dbh; bark gray-green; twigs gray to light brown, sometimes minutely pubescent on new growth, otherwise glabrous, leafing internodes (0.8–)1.2–2.4(–3.2) mm diam.; stipules fused, caducous. Leaves elliptic to broadly elliptic or obovate, (3.6–)4.5–9.5(–11.6) × (1.6–) 2.3–4.9 cm; base convex to broadly cuneate; apex rounded to cuspidate or obtuse (retuse, short-acuminate); margin entire, glands inconspicuous; secondary veins (5–)7–10 per side, sometimes with intersecondary veins almost equally large; both surfaces glabrous, drying pale to medium or olive-brown; petiole glabrous, 4–10 mm. Inflorescences mostly pseudoterminal, confined to twig apices, racemose to paniculate, 3.5–11.5(–20) cm; rachis pubescent, especially towards apex; bracts and bracteoles 3.5–5(–7) mm long, short-pubescent and ciliate; flowers mostly borne in pairs or gathered in widely-spaced clusters. Flowers 6–7(–8)-merous, white; sepals elliptic when young to narrowly elliptic or oblong-elliptic, becoming oblanceolate, 4.8–9 mm in flower, (7–) 8.5–10 mm in early fruit, entire adaxial and abaxial surfaces of sepals short-pubescent, base of calyx cup sericeous; sepal glands glabrous; petals lanceolate to narrowly ovate or narrowly oblong-ovate, 3–4 mm in flower, 4–5.5 mm in early fruit, both surfaces velutinous; filaments glabrous (rarely sparsely pilose), (1.5–) 2.2–2.8 mm; anthers 0.5–0.6 mm; styles (2–) 2.4–3 mm.

Vernacular names and use. – “Fotsiakara” (Service Forestier 21504); “Fotsiankara” (Service Forestier 13984, 21504 [Antsakagénéral dialect]); “Fotsivony” (Service Forestier 6390); “Hazofotsy à grandes feuilles” (Service Forestier 3796); “Hazombato” (Service Forestier 14719); “Kamirisa” (Antilahimena et al. 4863); “Ramanerika” (Service Forestier 14566).

Wood is used for construction and firewood (Service Forestier 21504).

Distribution, ecology and conservation status. – Homalium ciliolatum is confined to the southeastern regions of AtsimoAtsinanana, Vatovavy-Fitovinany, and Anosy. It is usually found near the coast at low elevations, but the type was probably from a mid-elevation forest. Reported substrates include basalt and rocky soil; habitats include forest and savoka (disturbed grassland). As many as ten subpopulations have been collected in the past (older locality data are imprecise). However, it has only been collected twice in the past 54 years, though much of its habitat is relatively accessible, so it is evidently rare. From all historical localities, the Extent of Occurrence is calculated as c. 15,980 km ² and the Area of Occupancy as 40 km ². Most historical populations were from land that has been subject to serious anthropogenic damage in the intervening decades and is still not protected. Therefore a preliminary assessment of its conservation status is “Vulnerable” [VU B1ab(iii)+ 2ab(iii)], but this is likely to underestimate the degree of threat it faces.

Notes. – Homalium ciliolatum was described by SLEUMER (1973) as a variety of H. nudiflorum , from which it is most obviously separated by its densely pubescent flowers. The petals are velutinous on both surfaces; the basal part of the calyx externally is densely sericeous, and the remainder of the sepals are short-pubescent and ciliate. Also, the upper portions of the inflorescence rachis and the bracts and bracteoles are pubescent, and the bracts and bracteoles short-ciliate. The petals appear often to remain curved over the ovary before fruit develops. It is likely that no fully mature perianths have been seen and the final size is larger than the range reported here. The distribution of H. ciliolatum is more southerly than that of H. nudiflorum and it is confined to lower altitudes. Two other species herein excluded from the H. nudiflorum complex, the newly described H. antilahimenae Wassel & Appleq. and H. tenue Wassel & Appleq. , also have calyces much more pubescent than those of H. nudiflorum . Homalium ciliolatum is distinguished from these by the distinctive long-sericeous indument of the calyx cup, which is not seen in any other species, and by having most flowers borne in pairs.

Service Forestier 14566 at P was stated ( SLEUMER, 1973: 299) to be the “ holotype ” of H. nudiflorum var. ciliolatum . There are in fact two duplicates of this collection at P, which are therefore syntypes. The duplicate designated herein as lectotype is in better condition and has better original label data.

Additional materials examined. – MADAGASCAR. Reg. Anosy [Prov. Toliara]: Iabakoho , Antsontso , Ivohibe forest , 24°34'10"S 47°12'37"E, 41 m, 24.V.2006, fr., Antilahimena et al. 4863 ( MO, P); forêt d’Androkabe, FortDauphin , 15.VIII.1951, fr., Service Forestier 3796 ( P). Reg. Atsimo-Atsinanana [Prov. Fianarantsoa]: Vangaindrano, Vohipaho , 23°31'40"S 47°29'46"E, 73 m, 17.IX.2009, fl., Andriamihajarivo et al. 1701 ( MO); Farafangana, Ihorombe, Mahatsinjoriaka , 23.X.1952, fr., Service Forestier 6390 ( P); Farafangana, Amporofo , 26.VII.1955, fr., Service Forestier 13984 ( P); Farafangana, Bekaraoka , 8.X.1963, fl., Service Forestier 21504 ( MO, P); S de Farafangana, rte de Manombo , aux P.K. 20– 21, 14–17.X. 1964, fr., Service Forestier 23613 ( P). Reg. Vatovavy-Fitovinany [Prov. Fianarantsoa]: Mananjary, Ambohinihaonana , 2.VI.1954, fl., Service Forestier 14476 ( P); Mananjary, Vohilaba, Ambodononoka , 20.VI.1954, fl., Service Forestier 14719 ( P).