Rhodiola

noun

Herbs perennial, with some dimorphism. Rhizome a fleshy caudex, thick or slender, apex usually at or slightly above ground level. Caudex leaves present, usually reduced and scalelike, but sometimes with well-developed leaf blade. Flowering stems 1 to many, arising from axils of caudex leaves, annual, simple, leafy; dried remains of old stems sometimes persisting. Stem leaves usually alternate, occasionally verticillate or opposite, simple, fleshy. Inflorescences terminal, a simply or compoundly corymbiform or dichotomous cyme, less often 1-flowered, rarely a helicoid cyme or with additional axillary inflorescences arising from distal leaf axils, usually bracteate and pedunculate. Flowers usually bisexual, sometimes unisexual (when plants dioecious, or gynodioecious in Rhodiola alsia subsp. alsia and rarely in R. purpureoviridis subsp. phariensis). Calyx (3 or) 4- or 5(or 6) -parted. Petals ± free, as many as sepals. Stamens in 2 series, usually 2 × as many as petals; antepetalous stamens adnate to basal part of petals; anthers mostly purple before anthesis, later turning yellow, basifixed or less often dorsifixed, 2-loculed. Nectar scales linear, oblong, suborbicular, or quadrangular. Ovary superior; carpels as many as petals. Follicles few to many seeded.