PRIMULACEAE Primrose Family | The family contains 22 genera and ca. 1000 species, occurring mainly in temperate and mountainous regions of the northern hemisphere. Twelve genera and 517 species are widely distributed throughout China, but are represented mostly in the S and W regions
Herbs perennial or annual, rarely suffruticose. Leaves alternate, opposite, or whorled, often all basal, simple, entire to lobed. The leaves are opposite or alternate, or form a rosette at the base of the stem, and are usually undivided. The leaves and stem may be hairy. The calxy is formed of five parts joined into a tube which remains after the flower dies, and inside which the seed pod develops. Flowers solitary or in panicles, racemes, or umbels, usually with bracts, perfect, (4- or)5(--9)-merous, often heterostylous (Primula). Calyx persistent. Corolla gamopetalous, actinomorphic, rarely absent (Glaux). Stamens as many as and opposite corolla lobes, ± epipetalous, occasionally with scalelike staminodes. Filaments free or connate into a tube at base. Ovary superior, rarely semi-inferior (Samolus), unilocular; placentation free central; style simple; stigma inconspicuous, capitate. Fruit a capsule, dehiscing by valves, rarely circumscissile or indehiscent. Seeds many or few; embryo small, straight, surrounded by endosperm. The seed pod forms inside the calyx and is composed of five parts joined into a single chamber. There are usually many small seeds. Most members of this family have some sort of storage organ to enable them to overwinter. This may be obviously enlarged, as in the Cyclamen tuber (corm), or just thickened roots with a resting bud, as in the many species of Primula. |
