Homalium perrieri Sleumer

Applequist, Wendy L., 2018, A revision of the Malagasy species of Homalium sect. Blackwellia (Salicaceae), Candollea 73 (2), pp. 221-244 : 239-240

12. Homalium perrieri Sleumer in Bull. Jard. Bot. Natl. Belg. 43: 257. 1973.

≡ Homalium buxifolium H. Perrier in Mém. Mus. Natl. Hist. Nat. 13: 286. 1940 [nom. illeg.] [non Däniker, 1933].

Holotypus: MADAGASCAR. Prov. Antsiranana: Massif de Manongarivo , versant de Sambirano , 500 m, V.1909, fl., Perrier de la Bâthie 4620 ( P [ P04734362 ]!; isotype: L [ L0010989 ] image seen) .

Tree to 14 m, 20 cm dbh, or large shrub; young twigs minutely pubescent. Leaves elliptical to broadly elliptical (somewhat ovate or obovate, suborbicular), 0.5 – 2.3 × 0.3 – 1.4 cm; petiole 1 – 1.5(– 2) mm; base rounded to convex; apex acute with rounded tip; margins crenateserrate, with glands elongated in tooth apices, often producing exudate; adaxial surface drying dark brown, abaxial surface brown; domatia occasionally present in axils of secondary veins. Inflorescences racemose, lateral, few-flowered, (0.8 –)1.4 – 3(– 3.8) cm, minutely to short-pubescent; flowers pedicellate with pedicels 0.5– 1.4(–2.5) mm; bracts 0.4–0.8 mm. Flowers 6–7-merous; calyx tube funnelform with base broadening in fruit, sparsely long-pubescent (to sparsely pilose); sepals ligulate (narrowly elliptical) with acute apex, 1–2(–3.1) mm; petals ligulate (narrowly spatulate to narrowly oblanceolate-elliptical) with acute apex, 1.3–2.1(–3.3) mm; sepals and petals pale yellow (to pale beige, white, reddish white), probably moderately accrescent, from substantially longer than calyx tube (especially in fruit) to equal in length, ascending (partly spreading to reflexed), long-ciliate, abaxial surface sparsely long-pubescent (to sparsely pilose), adaxial surface sparsely pilose to glabrate; sepal glands pilose; filaments 1–2.6 mm, sparsely pilose (moderately pilose, glabrous); ovary pilose; styles 4, 1.2–2.5 mm, basally pilose.

Vernacular names. – “Beando” (Bernard et al. 72); “Hazombato” (Rakotomalaza 10); “Maroankoditra” (Schatz & Antilahimena 4019).

Distribution, ecology and conservation status. – Homalium perrieri is native mostly to mid-elevation humid forest (to low-elevation or moderately high-elevation) in Antsiranana and northern Toamasina. It has been reported to occur on basalt and near water. There are at least six distinct populations, and the range includes the protected areas of Manongarivo and Anjanaharibe Sud, so its conservation status is tentatively estimated as “Least Concern” [LC].

Notes. – Homalium perrieri is among the species with racemose inflorescences and pubescent sepal glands. It is most similar to H. viguieri H. Perrier , which has usually sessile flowers with broad sepals and petals, and H. micranthum , which has usually much larger leaves and usually larger inflorescences. Leaves of pressed specimens of H. perrieri often appear almost distichously arranged. It is easily distinguished from the other very small-leaved species in this group, H. myrtifolium , which has obovate pale-drying leaves with cuneate bases, strongly ascending secondary veins, and small marginal glands that do not produce noticeable exudate.

Ravelonarivo & Rabesonina 646, from a very high altitude in Antsiranana, is a particularly problematic specimen. It has much larger leaves (to 3.3 × 1.7 cm) than other specimens, whose leaves are always less than 2.4 cm long, sometimes much less; the sepals and petals are usually reflexed shortly after anthesis. The leaves appear distichous and the inflorescences are very short, like H. perrieri ; hence identifying this as a small-leaved H. micranthum is not satisfactory. It might be suspected of being a distinct locally endemic taxon, but there is not enough material available to describe it. Further collections from the area would be desirable.

Homalium perrieri was a replacement name for H. buxifolium H. Perrier [nom. illeg.]. As far as is known, there was initially only one duplicate of the type collection, which is the holotype. The “isotype” at L, like most cited type duplicates at L., consists of a few leaves plainly borrowed after the fact from a complete specimen housed elsewhere, and does not have equal standing.

Additional material examined. – MADAGASCAR. Prov. Antsiranana: Antalaha , Ambohitralalana ( Cap-Est ), forêt Tanandavehely , 15°18' S 50°29' E, 0–15 m, 9.XII.1994, fl., Bernard et al. 72 ( G, MO, P) ; E of Ankaramy , Réserve Spéciale of Manongarivo , Bekolosy , 14°02'S 48°19'E, 800–1100 m, 7–12.XII.1992, fl. & fr., Malcomber et al. 1984 ( MO, P) ; E of Ankaramy , Réserve Spéciale de Manongarivo , Antsatrotro , 14°05'S 48°23'E, 600–900 m, 26–30.III.1993, fl. & fr., Malcomber et al. 2326 ( MO, P) ; E of Ankaramy Be , Manongarivo Réserve Spéciale , Bekolosy , 14°02'S 48°18'E, 1000–1200 m, 4.XII.1993, fl. & fr., Malcomber & Rakotomalala 2616 ( MO, P) ; E de Ankaramy-be , Réserve Spéciale de Manongarivo , Bekolosy , 14°04'S 48°17'E, 1000–1480 m, IV.1993, fl., Rakotomalaza 10 ( MO, P) ; Andravinambo, forêt de Tsihomanaomby , 14°06'S 50°00E, 23.I.2014, fl., Rakotonirina et al. 413 ( MO) ; Réserve Spéciale Anjanaharibe-Sud , village de Mandritasrahely , 14°43'10"S 49°27'12"E, 1700 m, 14.II.1995, fl., Ravelonarivo & Rabesonina 646 ( G, MO, P) ; Réserve Spéciale #5 , Manongarivo , W slopes of Antsatrotro , 14°08'S 48°21'E, 800 m, 23–25. III.1991, fl. & fr., Schatz 3216 ( MO, P) . Prov. Toamasina: Maroantsetra , fkt. Anjiahely , forest Ankahaminivola , 15°23'57"S 49°26'08"E, 780 m, 15.XII.2002, fl. & fr., Antilahimena et al. 1490 ( MO, P) ; Ankirindro massif , slopes above village Ambodivato , 15°19'13"S 49°33'29"E, 150 m, 20.XI.2002, fl., Schatz & Antilahimena 4019 ( G, K, MO, P) ; bassin de la Fananehana , massif de l’Androrona , crête terminale , 850 m, II.1954, Service Forestier 9001bis ( P) .