It is a perennial herb, 20-35 cm tall, with entire plant hairless, gray-green, rough along the stem edges, leaf margins, and midrib on the back, all with small milk protuberances. It has slender roots. The stems are tufted, erect, lower branches with four edges. The leaves are linear-lanceolate to linear, 2-4.5 cm long, 2-4 mm wide, pointed at the apex, slightly narrowed at the base, with short margin hairs, stalkless, pale green, hairless on both sides, and with a prominent midrib.
St. dilleniana Moench, St. glauca With., St. hsinganensis Kitagawa
It has an ovoid to oblong-ovoid capsule, slightly longer or nearly equal to persistent sepals, with numerous seeds; seeds are small, nearly round, slightly flattened, dark brown or blackish-brown, with distinct wrinkled convexities on the surface.