Homalium viguieri H. Perrier

Applequist, Wendy L., 2018, A revision of the Malagasy species of Homalium sect. Blackwellia (Salicaceae), Candollea 73 (2), pp. 221-244 : 242

15. Homalium viguieri H. Perrier in Mém. Mus. Natl. Hist. Nat. 13: 287. 1940.

Lectotypus (designated by SLEUMER, 1973: 253): MADAGASCAR. Prov. Toamasina: Prov. d’Andovoranto , district de Moramanga , berges du Mangoro près d’Ankarefo , 800 m, 10.XI.1912, fr., Viguier & Humbert 1188 ( P [ P04679649 ]!) . Syntypi: MADAGASCAR: sine loco, s.d., fr., Humblot 609 ( P [ P04679644 ]!; K [ K000231503 ] image seen, S [ S10-10215 ] image seen, US [ US00603579 ] image seen). Prov. Toamasina: Ambatovola , Vohitra , 700 m, I.1928, fl. & fr., Perrier de la Bâthie 18374 ( P [ P04679643 ]!) .

Shrub to 4 m or small tree, sometimes lianescent; young twigs minutely pubescent. Leaves broadly elliptical to elliptical (obovate to broadly obovate, rarely to broadly ovate or suborbicular), 2–5.6 × 1.1–3.8 cm; petiole 1.5–3(–4) mm; base convex to rounded or cuneate; apex rounded to acute or obtuse (short-acuminate); margins serrulate, with glands usually elongated, forming teeth apices, rarely small and imbedded in margin; adaxial surface drying dark grey to blackish, abaxial surface brown. Inflorescences racemose, lateral, 1.3–6.1(–7.5) cm, pubescent; flowers normally sessile (short-pedicellate); bracts linear to lanceolate or spatulate, 0.8–1.2(–1.5) mm, often persistent. Flowers 6(7)-merous; calyx tube broadly funnelform with rounded base, sparsely pubescent to glabrate; sepals lanceolate-oblong to oblong or obovate with acute (cuspidate, rounded) apex, (0.7–) 1.1–1.9 mm; petals oblong-elliptical to obovate, oblong or spatulate with acute (cuspidate, rounded) apex, (1–) 1.3– 2.4 mm; sepals and petals white to greenish (purplish) white, little accrescent, about as long as calyx tube, soon spreading, usually reflexed after flowering, ciliate with widely spaced hairs especially in fruit, both surfaces sparsely pubescent to glabrate; sepal glands short-pubescent; filaments 1.7–3 mm, glabrous; ovary sparsely to moderately pubescent, sometimes becoming glabrate; styles (3)4, 1.7–3 mm, glabrate with few trichomes near base.

Vernacular names. – “Fanazava” (Réserves Naturelles 6891); “Hazondromifehy” (Réserves Naturelles 8704); “Lalona fotsy” (Réserves Naturelles 2807); “Maroankoditra” (Service Forestier 5718); “Marokoditra” (Service Forestier 3292); “Voafotsy” (Cours 289).

Distribution, ecology and conservation status. – Homalium viguieri is native to mid-elevation humid forests to 1100 m; it does not occur in the extreme north or southeast. This species appears to be uncommon, as the number of collections is small compared to some other species with equally wide distributions and the number of recent collections particularly small. The Extent of Occurrence is estimated as c. 66,400 km ² and the Area of Occupancy as 56 km ². It was collected several times in or around the protected area of Zahamena (= Perinet, Ambatondrazaka) but most of the habitat is unprotected, has suffered damage since the existing collections were made, and is at threat of further damage. Because over 10 distinct locations have been documented, this species would not meet the criteria for a conservation status of “Vulnerable”, but a status of “Near Threatened” [NT] might be appropriate.

Notes. – Homalium viguieri has pubescent sepal glands and racemose inflorescences; it is most similar to H. micranthum and the small-leaved H. perrieri . It is distinguished from similar species by its broad sepals and petals, which are spreading to reflexed shortly after anthesis, and usually sessile flowers. The inside of the ovary locule may be glabrous or sparsely pubescent. In these characters it seems to be the species of Homalium sect. Blackwellia that is most similar to the species of Homalium sect. Odontolobus .

One of the syntypes of H. viguieri enumerated above, Perrier de la Bâthie 18374, is herein doubtfully placed in H. micranthum . “ Homalium viguieri var. cuneiforme H. Perrier ”, based on Cours 289 ( PERRIER DE LA BÂTHIE, 1946), was not validly published because of the absence of a required Latin diagnosis. It was later sunk into H. viguieri ( SLEUMER, 1973) . It does not appear to represent a distinct infraspecific taxon.

Additional material examined. – MADAGASCAR. Prov. Antananarivo: La Mandraka , VIII.1906, fl., Alleizette 1018 ( P) ; Betsitra , près Analabe ( N Imerina ), X.1906, fr., Alleizette 1276 ( P) . Prov. Fianarantsoa: Vangaindrano , vallée de l’Itomampy , 700 m, VI.1914, fr., Perrier de la Bâthie 12660 ( P) ; Manakara , s.d., fr., Service Forestier 2749 ( P) ; P.K. 92 , route Farafangana à Vohipena , 3.IV.1951, fr., Service Forestier 3681 ( P) ; Andriodriotra, Antsindra , Ambohimanga Sud , 20.VII.1952, fr., Service Forestier 6381 ( P) . Prov. Toamasina: Andapanomby , Makira forest , Ampandisanana river , 15°21'04"S 49°06'53"E, 1007 m, 26.IV.2007, fl. & fr., Birkinshaw et al. 1666 ( G, MO) ; Manakambahiny , 1100 m, III.1938, fr., Cours 289 ( P) ; Mahanoro, riv. Andohasira , Ampasimpotsy , 19°53'54"S 48°47'27"E, 5 m, 22.VI.2010, fr., Rakotonirina 535 ( MO, P) ; R.N. III , Manaka Est , Ambatondrazaka , 8.III.1951, fr., Réserves Naturelles 2807 ( P) ; Menalamba, Perinet , 21.III.1951, fl., Réserves Naturelles 3292 ( P) ; ManakaEst , Ambatondrazaka , 6.II.1954, fr., Réserves Naturelles 6891 ( P) ; ibid loco, 30.III.1954, fr., Réserves Naturelles 6896 ( P) ; ibid loco, 12.III.1956, fl., Réserves Naturelles 8704 ( P [2 sheets]) ; Antsahatsaka, Beravina , Perinet , 7.IX.1952, fr., Service Forestier 5718 ( P) ; berges du Mangoro au N d’Ambodimanga , 21.I.1968, fl., Service Forestier 28127 ( P [2 sheets]) .