剪刀股 jian dao gu

Lapsana japonica N. L. Burman, Fl. Indica, 174. 1768; Barkhausia repens (Loureiro) Sprengel; Chondrilla debilis (Thunberg) Poiret; Ixeris debilis (Thunberg) A. Gray; I. debilis f. sinuata Franchet & Savatier; I. japonica f. dissecta Nakai; I. japonica f. integra (Kuntze) Nakai; I. japonica subsp. litoralis Kitamura; I. japonica var. litoralis (Kitamura) H. L. Li; I. japonica subsp. salsuginosa (Kitagawa) Kitagawa; I. japonica var. salsuginosa Kitagawa; Lactuca debilis (Thunberg) Bentham ex Maximowicz; L. debilis var. integra Kuntze; Picris repens Loureiro; Prenanthes debilis Thunberg; Youngia debilis (Thunberg) Candolle.

Herbs 15-35 cm tall, perennial, glabrous, rosulate. Taproot with lateral shoot-bearing roots producing secondary leaf rosettes. Stems several, flagelliform, long creeping above ground; nodes 1 to several cm apart, most with adventitious roots and a single leaf. Flowering stems from rosettes and leaf axils of creeping stems, erect, to 35 cm, with 0 or 1 leaf. Basal leaves present at anthesis, spatulate, elliptic, or almost linear, 3-25(-35) × 0.5-2(-3) cm, undivided or pinnatifid to pinnatipartite and sometimes lyrately so, base attenuate into a petiole-like portion, margin entire or sinuate-dentate, apex obtuse to acute and mucronulate; lateral lobes (if present) 1 to few pairs, triangular to elliptic, apex acute to obtuse. Stem leaves (if any) similar to basal leaves but smaller. Synflorescence laxly and weakly corymbiform, with 1-6 capitula. Capitula with 20-25 florets; peduncle wiry, 1-20 cm. Involucre cylindric to campanulate, (8-)10-12 × 4-5 mm at anthesis, to 1.4 cm in fruit. Phyllaries abaxially glabrous; outer phyllaries ovate to lanceolate, longest to 4 mm, apex acute; inner phyllaries 8, apex acute. Florets yellow, anther tube and style greenish to blackish upon drying. Achene brown, fusiform, 6-8 mm, apex attenuate into a filiform 2-3 mm beak. Pappus 6-8 mm. Fl. and fr. Mar-May. 2n = 48.

Sandy seashores, open, disturbed places in lowlands, along roads, fields; sea level to 500 m. ?Anhui, Fujian, Guangdong, Guangxi, ?Henan, Liaoning, Taiwan, Zhejiang [Japan, Korea].

In absence of any evidence that the holotype of the name Lapsana japonica was to be excluded from this taxon, japonica is used as the oldest epithet. The two sheets of the holotype, collected in Japan by C. Kleynhoff and preserved at G-Burman (G 00302006, digital images seen), carry material at early anthesis. Its involucres measure 8.5 mm at anthesis and are thus rather small, but similar small involucres have been seen occasionally also in material from China; otherwise the type material matches well the taxon. The name Ixeris debilis (based on Prenanthes debilis) has been used instead in works on the flora of Japan since the 1950s, while the basionym L. japonica has been omitted entirely.