Grewia L.

Scientific Description

Family Tiliaceae.

Habit and leaf form. Trees, or shrubs, or lianas (sometimes). Self supporting, or climbing. Leptocaul. Mesophytic. Leaves alternate; spiral, or distichous; petiolate; non-sheathing; simple. Leaf blades entire; conspicuously asymmetric, or not conspicuously asymmetric; usually palmately veined. Leaves with stipules. Stipules intrapetiolar; free of one another; caducous. Leaf blade margins entire, or serrate, or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (hairs stellate), or absent. Stem anatomy. Nodes tri-lacunar. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male, or functionally female. Unisexual flowers present, or absent. Plants hermaphrodite, or monoecious, or dioecious, or polygamomonoecious. Female flowers with staminodes. Male flowers with pistillodes (with rudimentary ovary and style).

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’. Inflorescence few-flowered. Flowers in cymes. The terminal inflorescence unit cymose. Inflorescences axillary; umbellate. Flowers regular; (4–)5 merous; cyclic, or partially acyclic. Sometimes the androecium acyclic. Floral receptacle developing an androphore. Free hypanthium absent. Hypogynous disk absent. Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; isomerous. Calyx (4–)5; 1 -whorled; polysepalous; imbricate; regular; without appendage on abaxial side. Epicalyx present, or absent. Corolla (4–)5; 1 -whorled; with prominent gland near base; polypetalous; imbricate, or contorted; regular; green to yellow, or orange, or white. Corolla members entire. Fertile stamens present, or absent (in female flowers). Androecium 8–40 (or more). Androecial members branched; maturing centrifugally; free of the perianth (inserted on an androphore); free of one another. Stamens 8–40 (or more); diplostemonous to polystemonous. Anthers dehiscing via pores, or dehiscing via short slits, or dehiscing via longitudinal slits; bilocular; bisporangiate. Fertile gynoecium present, or absent (in male flowers). Gynoecium 2–4 carpelled. The pistil 2–4 celled. Carpels reduced in number relative to the perianth, or isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 2–4 locular. Gynoecium stylate. Styles 1; apical. Stigmas 1; dry type; papillate; Group II type. Placentation usually axile. Ovules 2 per locule, or 4 per locule; ascending, or pendulous; apotropous; with ventral raphe, or with lateral raphe; arillate, or non-arillate; hemianatropous to anatropous.

Fruit and seed features. Fruit fleshy; not spinose; indehiscent; a drupe (1–4-lobed). Seeds endospermic. Endosperm oily. Seeds not conspicuously hairy. Cotyledons 2. Embryo straight, or bent. Micropyle zigzag. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Native of Australia. Australian states and territories: Western Australia, Northern Territory, Queensland, and New South Wales.