Family Gisekiaceae

Gisekiaceae Nak.

~ Phytolaccaceae, Molluginaceae

Habit and leaf form. Herbs (often diffuse with prostrate branches). Plants more or less succulent, or non-succulent. Annual to perennial. Mesophytic, or xerophytic. Leaves (pseudo-) whorled, or opposite; ‘herbaceous’, or fleshy; simple. Lamina entire; spathulate or linear. Leaves exstipulate. Lamina margins entire. Leaves without a persistent basal meristem.

Leaf anatomy. Stomata present; anomocytic.

Lamina dorsiventral. Cystoliths present.

Stem anatomy. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring. Vessel end-walls simple.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Plants dioecious.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence unit cymose. Inflorescences axillary; loose to dense axillary cymes. Flowers bracteate; bracteolate; pedicellate to sessile, small; regular. Floral receptacle with neither androphore nor gynophore. Free hypanthium absent.

Perianth sepaline (corolla absent); 5; 1 whorled. Calyx 5; 1 whorled; polysepalous; regular (the sepals equal, herbaceous with membranous margins); imbricate.

Androecium in male flowers, 5–15. Androecial members branched, or unbranched (in that the stamens often inserted in pairs or triplets); free of the perianth; basally coherent, or free of one another (?). Androecium exclusively of fertile stamens. Stamens 5–15; isomerous with the perianth to triplostemonous; filantherous (the subulate filaments basally compressed). Anthers dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. Anther wall of the ‘monocot’ type. Tapetum glandular. Pollen grains aperturate; 3-celled.

Gynoecium 3–5 carpelled. Carpels reduced in number relative to the perianth to isomerous with the perianth. Gynoecium apocarpous; eu-apocarpous; superior. Carpel stylate; with the short, ventrally decurrent style internally stigmatose; 1 ovuled. Placentation basal. Ovules campylotropous, or amphitropous (?); bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Synergids hooked (with filiform apparatus). Endosperm formation nuclear.

Fruit non-fleshy; an aggregate (5-carpelled). The fruiting carpel indehiscent; membranous. Seeds non-endospermic. Perisperm present. Embryo “annular” or curved.

Physiology, biochemistry. Proanthocyanidins absent. Betalains present. C4. C4 physiology recorded directly in Gisekia pharnaceoides. Anatomy C4 type.

Geography, cytology. Holarctic, Paleotropical, and Cape. Sub-tropical and tropical. Arabia, tropical and South Africa to India, Sri Lanka and Indo-china.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales.

Species 5. Genera 1; Gisekia.