General: Perennial herb from a taproot; stems 1 or more, erect to decumbent, glabrous, 30-60 cm tall/long.
Leaves: Basal leaves several, oblong-lanceolate, 7-9 cm long, 1-2 cm wide, glabrous; stem leaves opposite, 4-10 pairs, becoming lanceolate and only slightly reduced above, mostly 4-9 cm long, broadly short-stalked, the base sheathing; stipules lacking.
Flowers: Inflorescence of 3-30 flowers in densely crowded clusters; petals 5, white to more usually pink or red, with narrow claws about equalling the calyces, the blade more or less egg-shaped, 6-10 mm long, wavy-toothed; sepals 5, green below and often violet above, united, forming a glabrous tube about 15 mm long, about 40-nerved.
Fruits: Capsules oblong, 9-13 mm long, 4-valved; seeds compressed, concave on one side.
If more than one illustration is
available for a species (e.g., separate illustrations were provided for two
subspecies) then links to the separate images will be provided below.
Note that individual subspecies or varietal illustrations are not always available.
