Solmsia Baill.

Rogers, Zachary S. & Fuentes-Soriano, Sara, 2021, Solmsia Baill.: a taxonomic revision of an endemic New Caledonian genus of Thymelaeaceae, Adansonia (3) 43 (12), pp. 125-150 : 138-139

Genus Solmsia Baill.

Adansonia, Recueil d’Observations botaniques 10: 37, 38 ( Baillon 1871) [12.VI.1871]. — Type: Solmsia calophylla Baill. — Lectotype designated [as “Leitart”] by Domke (1934: 117).

ETYMOLOGY. — Baillon chose the name Solmsia in honor of Hermann [Maximilian Carl Ludwig Friedrich zu] Solms-Laubach (1842-1915), a German botanist who published research on Chloranthaceae R. Br. ex Sims , Lennoaceae Solms , and several parasitic plant groups, but who himself never visited New Caledonia.

DESCRIPTION

Shrubs, rarely treelets or small trees; intraxylary phloem absent; plants functionally dioecious, most vegetative structures (e.g., young branches, petioles, abaxial surface of leaf blades) and many reproductive structures (e.g., buds, pedicels, sepals, fruit pericarp) densely velutinous; pubescence tan-golden or whitish; trichomes simple, very short, erect, soft.

Leaves

Simple, exstipulate and entire (all three family characters), phyllotaxy spiral, alternate (sometimes appearing subopposite when leaves crowded at distal tips of branches), petiolate, conduplicately folded in bud; epidermis with secretory cavities and mucilaginous cells, densely punctate; punctations usually translucent when fresh and blackish when dry; leaf blade obcordate or obovate, size variable (even on the same branch), very thick, tough and fibrous, texture coriaceous; surfaces discolorous, adaxial surface glabrous, shiny, abaxial surface initially densely velutinous, trichomes persisting and remaining dense (“chrysophylla form”) or becoming glabrescent (“calophylla form”); apex usually somewhat emarginate and terminated with a mucronate tip formed by a short extension of the distal end of the midrib; venation penninerved, Calophyllum -like, veins numerous, all equally thin, diverging from midrib at relatively wide angles then running ± straight and parallel to each other before finally joining with a distinct fibrous marginal nerve that outlines the blade.

Inflorescences

Axillary or pseudoterminal, congested or lax, pedunculate [cf. thyrsoid and analysis inWeberling & Herkommer 1989]; peduncles of variable lengths (up to 2.1 cm long), borne near the distal tips of the branches and usually in the axils of small leaves, terminus of peduncle usually branched into a few shorter secondary axes; secondary inflorescence axes of variable lengths (up to 1.1 cm long), each cluster apparently cymose and terminated with c. 5(-10) shortly pedicellate flowers.

Flowers

Unisexual (functionally), (3)4(5)-merous, staminate and pistillate flowers of similar shape and size, relatively small, pubescent; calyx fused proximally into a very short cupuliform or subcampanulate tube, with the distal part divided into (3)4(5) distinct sepals of± uniform shape and size, those slightly longer than fused portion of tube, calyx persistent through fruiting; sepals valvate, subtriangular or ovate-triangular, small, velutinous on both surfaces; petaloid scales absent; androecium diplostemonous, glabrous, persistent in fruit, in pistillate flowers with sterile anthers and shorter staminodial filaments, otherwise similar in flowers of both sexes.

Staminate flowers. With (6)8(10) fertile stamens, all free; filaments slightly extending beyond the sepals, S-shaped and folded in bud (and retaining shape after anthesis), inserted in a ring surrounding a small pistillode; fertile anthers extrorse, ± peltate; pistillode (3)4(5)-locular; rudimentary ovary often with minute ovules; stylode reduced, apex minutely capitate with a rudimentary stigmatic surface.

Pistillate flowers. With (6)8(10) staminodia, all free, usually about half as long as sepals and fertile stamens in staminate flowers; sterile anthers minute; gynoecium (3)4(5)-locular; ovary densely tomentose-sericeous, sessile; carpels uniovulate; ovules anatropous, pendulous; subgynoecial disc absent; style terminal, short, slightly longer than sepals, relatively thick, straight in bud, persistent in fruit; stigma capitate, well-developed.

Fruits

Loculicidal capsules, (3)4(5)-carpellate, obovoid or obpyramidal; pericarp densely velutinous; fruit valves inwardly partitioned (with a septum) at the middle.

Seeds

Compressed laterally, seed coat crustaceous and black, covered with a thin transparent or translucent orange-yellow membrane, outer epidermis of membrane pubescent; chalazal end with a horn-shaped arillate appendage [for illustrated seed and comparisons with several species in other closely related genera of Thymelaeaceae , see Domke 1934: pl. 5, fig. 43b]; endosperm abundant; embryo axile, with flattened, narrow cotyledons, hypocotyl short.