7. Tournefortia Linnaeus, Sp. Pl. 1: 140. 1753.
紫丹属 zi dan shu
Argusia Boehmer ex Ludwig; Arguzia Ammann ex Steudel; Messerschmidia Linnaeus ex Hebenstreit.
Shrubs, climbing shrubs, trees, or herbs. Leaves alternate, petiolate, entire. Cymes terminal or axillary, corymbose, ebracteate. Calyx 4- or 5-parted, not changing in fruit; lobes narrow. Corolla white or pale green, usually funnelform; tube pubescent outside, usually exceeding calyx; throat unappendaged; lobes 4 or 5, overlapping or valvate in bud, spreading at anthesis. Filaments short, inserted on corolla tube; anthers ovate to oblong, mucronate or obtuse at apex. Disc slightly convex or sometimes nearly cupular. Ovary 4-loculed; ovules 1 per locule, pendulous. Style terminal; stigma entire or 2-cleft, base fleshy, ringlike, inflated. Drupes with watery, sticky, or corky mesocarp, endocarp divided at maturity into 2 2-seeded or 4 1-seeded mericarps, sometimes 1 seed sterile. Seeds oblique; cotyledons ovate or elliptic.
About 150 species: tropical and subtropical regions; four species in China.
Argusia (including Messerschmidia) has often been regarded as a distinct genus of three species of seashore plants. It is distinguished from Tournefortia by the corky mesocarp, which is an adaptation to dispersal by seawater. True Tournefortia has fleshy fruit, and none of its species is a seashore plant. For a detailed discussion of the generic limits of Argusia and Tournefortia, see Al-Shehbaz (J. Arnold Arbor., suppl. ser., 1: 1-169. 1991).
