Homalium (sect. Eumyriantheia) Warb.
Creators: name: Applequist, Wendy L.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malpighiales
Salicaceae
Homalium

description: 4. Homalium sect. Eumyriantheia Warb.
in Engler & Prantl, Nat. Pflanzenfam. III(6a): 36. 1893.
÷ Myriantheia Thouars, Gen. Nov. Madagasc.: 21. 1806. ÷ Homalium [unranked as §] Myriantheia (Thouars) Baill., Bull. Mens. Soc. Linn. Paris 1: 576. 1886 [as Myrianthea]. ÷ Homalium sect. Myriantheia (Thouars) Kuntze in Post & Kuntze, Lex. Gen. Phan., Prop.: 285. 1903 [as Myriantheja].
Typus: Homalium laxiflorum (Tul.) Baill. (÷ Myriantheia laxiflora Tul.) (designated by Sleumer, 1973: 315).
Stipules axillary, free. Inflorescences racemose or paniculate; bracts ovate to deltoid, sometimes broadly, of small to moderate size; bracteoles usually 2 per flower, often borne on pedicel (1 per flower, or absent or rapidly caducous). Flowers pedicellate with pedicels articulated (in H. trigynum sessile or short-pedicellate); perianth 4-5(-6)-merous. Sepals oblong to elliptical, ovate or obovate, sometimes narrowly (oblanceolate), very little accrescent; calyx tube funnelform, in fruit becoming convex to cup-shaped or nearly hemispherical (in H. trigynum short-cylindrical or turbinate becoming broadly ellipsoid in fruit); sepal glands usually large, oblong to elliptical or irregularly trapezoid (semicircular), sometimes elevated. Petals obovate to oblanceolate (in H. trigynum to spatulate), similar to sepals in length or up to twice as long, spreading or ascending at anthesis, very little accrescent; sepals and petals not ciliate (appearing ciliolate in conjunction with overall surface indument). Stamens 3 (aberrantly 4, in H. boinense H. Perrier 5) per petal, inserted between glands; anthers dorsifixed, broadly oblong-elliptical with oblong-elliptical locules and a large connective, the slits of dehiscence nearly parallel. Upper surface of ovary conical, usually shallowly, to nearly flat in flower, in fruit sometimes becoming convex; styles 3-5, free to base or near base. Locule of fruit subglobose (in H. trigynum ellipsoid and partly filled with spongy tissue), glabrous (sparsely pubescent); seeds sometimes 1 (to 2) per fruit, large and subglobose to ellipsoid (possibly at least 4 in H. nobile Baill.).
Distribution. – Madagascar.
Species included. – Homalium boinense, H. brevipedunculatum Scott-Elliot, H. capuronii Sleumer, H. dorrii Appleq., H. graciliflorum Sleumer, H. laxiflorum, H. maringitra H. Perrier, H. nobile, H. oppositifolium (Tul.) Baill., H. pseudoboinense Appleq., H. pulchrum Sleumer, H. randrianasoloi Appleq., H. ranomafanicum Appleq., H. schatzii Appleq., H. trigynum.
Notes. – Sleumer (1973) wrongly corrected the name of Homalium sect. Eumyriantheia to “sect. Myriantheia ” and presumed it to have been based upon Thouars’ Myriantheia. The two were not nomenclatural synonyms, but because he explicitly treated them as such, he effectively designated the same type for both simultaneously.
Homalium trigynum has some unusual features that are similar to features common in sect. Blackwellia, which also occurs in Madagascar (see discussion above); molecular data regarding its relationships would be of interest. A recent revision describes five new species in the section (Applequist, 2016).
description: Published as part of Applequist, Wendy L., 2016, A reconsideration of the infrageneric classification of Homalium Jacq. (Salicaceae), pp. 231-256 in Candollea 71 (2) on pages 252-253, DOI: 10.15553/c2016v712a9, http://zenodo.org/record/5721656