Family Basellaceae

Basellaceae Moq.-Tand.

Including Anredereae (Anrederaceae) J.G. Argardh, Ullucaceae Nak.

Habit and leaf form. Herbs. Perennial; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves; rhizomatous, or tuberous. Self supporting, or climbing; the climbers stem twiners, or scrambling. Mesophytic. Leaves opposite, or alternate; somewhat fleshy; petiolate; non-sheathing; simple. Lamina entire; pinnately veined to palmately veined; cross-venulate. Leaves exstipulate.

Leaf anatomy. Stomata present; paracytic, or anomocytic and paracytic.

The mesophyll containing mucilage cells. Minor leaf veins without phloem transfer cells (Basella).

Stem anatomy. Cork cambium present; initially superficial. Primary vascular tissue comprising a ring of bundles; bicollateral (at least in the larger bundles). Internal phloem present (commonly?). Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with vessels. Vessel end-walls simple. Sieve-tube plastids P-type; type III (a).

Reproductive type, pollination. Plants hermaphrodite (mostly), or monoecious (? — at least sometimes ‘functionally unisexual’).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in panicles. Inflorescences terminal, or axillary; panicles, racemes or spikes. Flowers bracteate (the bracts small); bracteolate (the two bracteoles calyx-like, connate at the base or not, often winged and persistent in the fruit); regular (excluding paired bracteoles); 5 merous; cyclic; tricyclic, or tetracyclic (if the bracteoles regarded as ‘perianth’). Floral receptacle not markedly hollowed. Free hypanthium present. Hypogynous disk present; annular.

Perianth with distinct calyx and corolla (if the bracteoles are regarded as calyx, the calyx as corolla), or sepaline (the best interpretation?), or petaline; 5, or 7 (if the ‘bracteoles’ are mistaken for perianth); 1 whorled, or 2 whorled (if the bracteoles are included); anisomerous (if the bracteoles included); persistent. Calyx 5 (i.e. the true perianth), or 2 (i.e. the bracteoles); polysepalous (the true sepals and/or the bracteoles sometimes almost distinct), or gamosepalous (the bracteoles and/or the true sepals usually tubular below); persistent (both the bracteoles and the true calyx); imbricate.

Androecium 5. Androecial members adnate (to the base of the perianth members, or to the tube); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous; bent outwards in bud. Anthers dorsifixed; versatile; dehiscing via pores, or dehiscing via short slits, or dehiscing via longitudinal slits; tetrasporangiate. Microsporogenesis simultaneous. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; foraminate, or rugate (pantocolpate, or cuboid with a colpus on each furrow); spinulose; 3-celled (Andredera).

Gynoecium 3 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled (when mature). Gynoecium syncarpous; synovarious to eu-syncarpous; superior. Ovary 1 locular (though detectably trilocular in the very early stages of development). Gynoecium stylate. Styles 1, or 3; when separate, free, or partially joined; apical. Stigmas 3. Placentation basal. Ovules in the single cavity (of the mature ovary) 1; funicled; ascending; non-arillate; anatropous to campylotropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped. Endosperm formation nuclear.

Fruit non-fleshy; indehiscent; capsular-indehiscent (a utricle); enclosed in the fleshy perianth, or without fleshy investment (then surrounded by the winged bracteoles). Seeds non-endospermic. Perisperm present. Seeds with starch. Embryo well differentiated. Cotyledons 2. Embryo chlorophyllous; curved (semi-annular), or coiled.

Seedling. Germination phanerocotylar.

Physiology, biochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins absent. Flavonols present, or absent; when present, quercetin. Ellagic acid absent (2 genera, 2 species). Betalains present. Anatomy non-C4 type (Basella).

Geography, cytology. Tropical. Tropical America, Africa, Asia. X = 11, 12.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG (1998) Eudicot; core Eudicot; neither Rosid nor Asterid. APG 3 (2009) Order: Caryophyllales.

Species 25. Genera 4; Anredera, Basella, Tournonia, Ullucus.

Illustrations.
• Technical details: Anredera, Basella, Ullucus.

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