生活型

herb

形態特徵

• Annual or biennial herb, erect, 30-120 cm tall; stem subglabrous, somewhat glandularly hairy.
• Basal leaves usually pinnately incised or lobed, segments 2-4 pairs, 13-16 cm long, margins denticulate, acute to acuminate, cauline leaves unlobed or sometimes pinnate, 5-10 cm long, upper cauline leaves gradually becoming smaller and heart-shaped and clasping, midrib usually prickly setose.
• Inflorescence a narrow cylindrical panicle, 10-30 cm tall. Head ca. 8-10 mm across, peduncles 8-20 mm long. Involucre cylindrical, 6-10 × 3-4 mm, bracts glabrous, greenish, outer ones ovate, ca. 2-3 mm long, inner ones lanceolate. Florets 18-28, corolla yellow or pale-yellow, 8-10 mm long.
• Achenes elliptic, flat, dark-brown to black, ca. 2-3 × 1-2 mm, rough-hairy, several-veined on each face, beak ca. 5 mm long. Pappus white, ca. 5 mm long.

物候

Flowering time: May-Sept.

分布

• 台灣 : this species was found in an exposed area in the central part of western Taiwan and Penghu islands, mixed with low grasses and weeds on a roadside. Since 2007, the populations in Taiwan were stable or somewhat extended during the field observation.
• 世界 : This species is believed to have originated from Europe, the Mediterranean region. It was accidentally introduced into North America in the late 1890s, and was also distributed through Africa, and Asia.

引證標本

Taichung Co., Wujih Township: Near the Taiwan High Speed Rail (HSR) Taichung Station, May 15, 2007, T. W. Hsu 12720 (TNM); Same loc., May 25, 2007, C. M. Wang 10241 (TNM); Same loc., May 27, 2007, C. M. Wang 10254 (TNM). Same loc., July 7, 2007 C. H. Chen 8813 (TNM). Penghu Co., Makung City: Makung Port, 2nd Fishing Harbor, Aug 22, 2008, C. C. Wang s. n. (TNM).

參考文獻

• Chiu-Mei Wang and Chih-Hsiung Chen, Taiwania 55(3): 331-333. 2010.