Family Surianaceae

Surianaceae Arn.

Excluding Stylobasiaceae

Habit and leaf form. Trees and shrubs. Mesophytic and xerophytic (with Suriana coastal). Leaves small to medium-sized; alternate; spiral; ‘herbaceous’, or leathery (?); petiolate to sessile; non-sheathing; not gland-dotted; simple (mostly), or compound (Recchia). Lamina entire; acicular, or lanceolate, or oblanceolate, or oblong; one-veined, or pinnately veined (?); cross-venulate (?); attenuate at the base. Leaves exstipulate. Lamina margins entire.

Leaf anatomy. Extra-floral nectaries present (e.g. Cadellia), or absent. Abaxial epidermis not papillose. Mucilaginous epidermis absent. Stomata present; mainly confined to one surface (abaxial), or on both surfaces (Suriana); anomocytic, or anisocytic.

Adaxial hypodermis absent. Lamina dorsiventral, or isobilateral (?), or centric. The mesophyll without etherial oil cells; not containing mucilage cells.

Stem anatomy. Secretory cavities present, or absent. Cork cambium present, or absent; initially deep-seated, or superficial. Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids, or without fibre tracheids; of Suriana with libriform fibres. Vessel end-walls simple. Wood of Suriana storied; parenchyma of Suriana apotracheal and paratracheal.

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence unit cymose. Inflorescences axillary. Flowers bracteate (the bracts large in Suriana); bracteolate; small; regular; 5 merous; cyclic; pentacyclic. Free hypanthium present (inconspicuous), or absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous (below, the lobes acuminate); regular; persistent; imbricate; with the median member posterior. Corolla 5; 1 whorled; polypetalous; imbricate, or contorted (in Suriana maritima); regular; yellow. Petals shortly clawed.

Androecium (8–)10. Androecial members free of the perianth; markedly unequal (the inner shorter); free of one another; 2 whorled. Androecium exclusively of fertile stamens, or including staminodes (the inner or outer members often sterile or abortive). Staminodes when present, 1–5; ambiguously external to the fertile stamens, or in the same series as the fertile stamens, or internal to the fertile stamens; non-petaloid. Stamens 5, or (8–)10; isomerous with the perianth, or diplostemonous; oppositisepalous; alternating with the corolla members, or both alternating with and opposite the corolla members. Anthers dorsifixed (“basifixed and versatile” in Suriana maritima, according to Bello et al.); versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Tapetum glandular. Pollen grains aperturate; 3 aperturate; colporate (or colporoidate); 2-celled.

Gynoecium 5 carpelled (Suriana, Cadellia), or 1 carpelled (Guilfoylia), or 2–4 carpelled (?). Carpels reduced in number relative to the perianth, or isomerous with the perianth. Gynoecium monomerous, or apocarpous; of one carpel, or eu-apocarpous; superior. Carpel stylate; with a gynobasic style; 2 ovuled. Placentation (sub-) basal. Ovules funicled; ascending; collateral; non-arillate; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Endosperm formation nuclear. Embryogeny onagrad.

Fruit fleshy; an aggregate (of 3–5 carpels), or not an aggregate (when monomerous). The fruiting carpel indehiscent; nucular, or drupaceous, or baccate. Seeds more or less non-endospermic. Cotyledons 2 (usually thickened). Embryo curved (hippocrepiform), or bent.

Physiology, biochemistry. Not cyanogenic. Proanthocyanidins present, or absent. Ellagic acid absent. Saponins/sapogenins absent.

Geography, cytology. Sub-tropical and tropical. Atlantic tropical America, tropical East Africa, Madagascar, Mascarenes, Indian Ocean Islands, Ceylon to Malay Peninsula, Eastern Malaysia, Northeast and subtropical Australia, Formosa, Philippines.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae, or Rosiflorae (cf. Fernando et al 1993); if Rosidae, Rosales (or near Polygalales); (if Rutiflorae) Rutales. Cronquist’s Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Fabales.

Species 7. Genera 4 (with Stylobasium excluded); Suriana, Cadellia, Guilfoylia and Recchia.

Satisfactory representation of recent notions on the proper dispositions of genera previously referred to Simaroubaceae will necessitate thorough overhaul of the descriptions presented in this package (cf. Ixonanthaceae, Irvingiaceae, Kirkiaceae, Picramniaceae, Simaroubaceae, Stylobasiaceae). Meanwhile, details of this description are probably biased towards Suriana, pending acquisition of adequate data on the other genera. A detailed study of floral morphology and ontogeny by Bello et al. (2007) is restricted to Suriana maritima.

Illustrations.
• Technical details: Suriana (Lindley).
• Technical details: Suriana.