Plant 25–50 cm, monocarpic, glabrous throughout.Caudex simple.

植株25-50厘米，一次结果，全株无毛。

Stem straight, glabrous, muricate near nodes.

茎直，无毛，近节。

Young stems terete to frequently 4-angled or subalate, glabrous, puberulous, pubescent, or tomentose, often glabrescent.

嫩茎圆柱状到经地四棱形或似翼，无毛，被微柔毛，短柔毛，或被绒毛，后脱落。

Shrubs or small trees, usually erect, rarely viny or climbing, glabrous, rarely pubsecent, branches often inermous.

灌木或小乔木，直立，很少倾斜或攀援，无毛，很少短柔毛，枝经无刺。

Petals usually 5, rarely more, occasionally absent, white, pink, or red, glabrous or hairy, margin entire, rarely premorse.

花瓣5，很少更多，偶尔无，白色，粉红色，或红色，无毛或有毛，边全缘，很少啮蚀状。