Naumburgia thyrsiflora (Linnaeus) Reichenbach.

Herbs perennial, 30--80 cm tall, with horizontal rhizomes. Stems erect, usually simple, black glandular punctate, glabrous on lower part, puberulent on upper part. Lowest leaves scalelike, reduced. Leaves opposite, sessile, rarely indistinctly petiolate; leaf blade lanceolate to elliptic-lanceolate, 5--15 X 0.6--2 cm, lower part tapering toward obtuse or semi-clasping base, abaxially glabrous except for sparingly villous midvein, sparsely black glandular punctate, adaxially glabrous, apex acute to acuminate. Racemes dense, capitate or spikelike, pedunculate, 1--3 cm, confined in axils of medial and upper leaves; peduncle 1.5--3 cm, glabrous or sparingly villous. Pedicel 1--3 mm, glabrous or sparingly villous. Calyx 2--3.5 mm, parted nearly to base; lobes usually 6 or 7, linear-lanceolate, black glandular punctate. Corolla cream-yellow, parted nearly to base; lobes usually same number as calyx lobes, linear, 5--6 X 0.5--1 mm, black glandular punctate and striate. Stamens ca. as long as to longer than corolla; filaments 4--5 mm, nearly free, adnate to base of corolla; anthers oblong, dorsifixed, ca. 1 mm. Ovary sparingly puberulent; style 4.5--6 mm. Capsule subglobose, ca. 2.5 mm in diam. Fl. May-Jun. 2n = 20, 40, 42.

Bog margins, marshes, moist meadows. Heilongjiang, Jilin, Nei Mongol, Shaanxi, Yunnan [Circumboreal].