Homalium, Jacq.

Applequist, Wendy L., 2016, A reconsideration of the infrageneric classification of Homalium Jacq. (Salicaceae), Candollea 71 (2), pp. 231-256 : 249-250

Key to recognized sections of Homalium

1. Stamens in fascicles of 2 or more per petal .................... 2

1a. Stamens 1 per petal....................................................... 5

2. Stamens partly inserted on the petals; petals shorter than the sepals in flower and/or fruit (to nearly equal); perianth accrescent, the sepals often more so than the petals .......... ................................................................ 7. Sect. Pierrea

2a Stamens all inserted between the sepal glands; petals longer than or equal to the sepals; perianth often moderately accrescent, if so then the petals at least as much so as the sepals....................................................................... 3

3. Calyx tube turbinate to narrowly funnelform or tubular, at least in fruit (rarely funnelform or hardly visible in flower), usually prominently ridged; sepals and petals 5-12(-13), usually ciliate with usually long and/or stiff trichomes; upper surface of ovary usually narrowly conical (rarely nearly flat), the styles free to near base; ovary locule elongated and narrow (rarely to obconical), pubescent; Asia, Malesia, Pacific................................. 8. Sect. Polyanthera

3a Calyx tube broadly funnelform, in fruit becoming convex to cup-shaped or nearly hemispherical (in H. trigynum short-cylindrical or turbinate becoming broadly ellipsoid in fruit), not prominently ridged; sepals and petals 4-7, not ciliate (ciliolate); upper surface of ovary usually broad, nearly flat to conical, in fruit conical to convex, the styles free to near base or fused into a short stylar column; ovary locule broad, ovoid to ellipsoid or subglobose, pubescent or glabrous; Africa, Madagascar, Americas................... 4

4. Petals 4-5(-6), ovate to elliptical (to somewhat oblong, broadly spatulate), moderately accrescent; upper surface of ovary prominently conical; styles usually fused at base into a short distinct column (free to near base, fused for most of length); locule of fruit ellipsoid with a shallowly to strongly conical apex, more or less pubescent; Central and South America, Africa ................ 1. Sect. Homalium

4a. Petals 5-7, obovate to oblanceolate (in H. trigynum to spatulate), little accrescent; upper surface of ovary nearly flat to shallowly (moderately) conical in flower, in fruit moderately conical to convex; styles free to near base; locule of fruit subglobose, glabrous (in H. trigynum ellipsoid, partly divided or filled with spongy tissue, sparsely pubescent); Madagascar.............. 4. Sect. Eumyriantheia

5. Bracts very large, reniform, persistent, enfolding and completely or almost completely concealing flowers............... .............................................................. 2. Sect. Antinisa

5a. Bracts variable in size and persistence, not large enough to cover flowers ................................................................. 6

6. Stipules fused opposite petiole (in H. intercedens free and axillary); sepals longer than (in H. louvelianum about equal to) petals ...................................................... 5. Sect. Nisa

6a. Stipules free, axillary; sepals shorter than or about equal to petals ............................................................................. 7

7. Sepals reduced to minute deltoid teeth or small and ligulate to lanceolate-oblong; petals small, ovate to transversely ovate or narrowly oblong-lanceolate to oblong-elliptical, not or very little accrescent; styles free to base, often short; upper surface of ovary broad and nearly flat (to convex) in flower, becoming convex in fruit ...... 6. Sect. Odontolobus

7a. Sepals variable in relative size, not minute; petals usually broadest above the midpoint or ligulate to narrowly elliptical or oblong (rarely to linear, oblong-ovate, or narrowly deltoid), at least modestly accrescent; styles free, with ovary conical in flower, or lower portion of styles usually fused, with ovary nearly flat to moderately conical or convex in flower, in fruit usually becoming conical to convex unless apical surface is very narrow.......................................... 8

8. Bracteoles usually absent; calyx tube turbinate to narrowly funnelform or tubular (seldom short, funnelform), usually prominently ridged; perianth 5-12(-15)-merous, usually ciliate, usually with long and/or stiff trichomes; upper surface of ovary conical in flower, usually prominently so in fruit; styles free (though upper part of narrowly conical ovary may resemble a stylar column).......... .......................................................... 3. Sect. Blackwellia

8a. Bracteoles present, caducous or persistent; calyx tube broadly funnelform, in fruit convex to nearly hemispherical (in a few species cylindrical and ridged or grooved); perianth (4-)5-6(-8)-merous, not ciliate or ciliate with soft, often short trichomes; upper surface of ovary nearly flat (to shallowly convex or conical) at anthesis, in fruit convex or conical (or remaining nearly flat); styles usually partly fused (seldom quite short)............................................. 9

9. Bracts and bracteoles usually small and caducous; calyx tube funnelform, in fruit cup-shaped, not prominently ridged; sepals acute, often little accrescent, not strongly curved over fruit; Africa .......... 10. Sect. Symphyostylium

9a. Bracts broad, bracts and bracteoles persistent; calyx tube tubular to funnelform, in fruit tubular to cup-shaped or ellipsoid and often ridged or grooved; sepals accrescent, usually broad to apex, tending to curve over the fruit; Madagascar......................................... 9. Sect. Rhodonisa

Taxonomic treatment