Plumbaginaceae

Abstract

Shrubs, lianes, or herbs. Leaves simple, entire to lobed, spirally arranged, sometimes auriculate, exstipulate, rarely scaly; foliage usually with scattered chalk glands exuding water and calcium salts, and often with raised mucilage-glands. Inflorescences bracteate, racemose or often cymose (thyrsic), simple or compound; bracts often sheathing, dry and membranous. Bracteoles 2(−1). Flowers bisexual, actinomorphic, 5-merous, often heterostylous. Calyx persistent, gamosepalous, rarely chorisepalous, forming a 5- or 10-ribbed tube, often petaloid, mostly scarious. Petals connate or nearly free, often persistent; lobes contort. Disk often present, sometimes as five glands alternating with the stamens. Stamens 5, opposite the corolla lobes, the filaments mostly free in the Plumbaginoideae, basally adherent to the petals in the Staticoideae. Anthers tetrasporangiate, dithecal, opening lengthwise. Gynoecium 5-carpellate, fused to form a unilocular ovary with 5 distinct styles or a single, apically lobed style; stigmas dry, papillate, capitate to cylindric; ovule solitary, basal, anatropous, bitegmic, crassinucellar, on a slender funicle. Fruit a dry, membranous, 1-seeded achene, partly or wholly enclosed by the persistent calyx, or sometimes a capsule dehiscing circumscissile or upwards directed by valves. Seed with a straight embryo and with copious endosperm containing solitary starch grains, sometimes without starchy endosperm; x usually = 6–9.