生活型

herb

形態特徵

• Erect biennial herbs, sometimes diffuse and decumbent, stems terete, 20–60 cm tall, well branched from lower part of stem, terminating in 1-few heads, glabrous.
• Radical leaves rosulate, oblong-spatulate, 8–15 cm long, 3–5.5 cm wide, apex round, base cuneate, margins entire, ciliate, nearly glabrous on both surfaces, withered at anthesis. Cauline leaves green, thin, elliptic-lanceolate or obovate, apex round or obtuse, base narrowed, sessile, 4.5–5.5 cm long, 13–23 mm wide, hispid on veins on lower surface, margins entire, ciliate; usually bimodal in size and shape, leaves below lowest branch larger, leaves on branches smaller, elliptic-lanceolate to oblong-lanceolate, 2–3 cm long, 6–10 mm wide.
• Heads many, 2.5–3.5 cm across, peduncle 2–3 cm long, often solitary, terminating branches, in loose corymbs. Involucre hemispheric or bowl-shaped, 7–10 mm long, 12–16 mm broad, bracts green, herbaceous, 2 or 3 seriate, subequal, linear lanceolate or subulate, entire, acuminate to attenuate-acuminate, 4.5–7.5 mm long, 1–1.7 mm wide, sparsely hirsute outside, margins ciliate. Ray florets 15–22 in 1 or 2 series or sometimes lacking, when present ligules white, 8.5–12 mm long, 2–3 mm wide, tube 1 mm long. Disc florets 4–4.5 mm long, unequally 5-lobed. Pappus dimorphic, that of ray florets white, 0.5–1 mm long, forming a crown, that of disc florets reddish, 3–4 mm long.
• Achenes brown, obovate, compressed, 2.5–3 mm long, 1.5–2 mm broad, finely sericeous, sparsely glandular punctate apically.
• Chromosome number, 2n = 36 (Peng & Hsu, 1978); 2n = 54 (Gu, Cathaya 1: 3. 1989). <li><i>Aster oldhamii</i> differs from <i>A. hispidus</i> by its dimorphic leaves, with the larger leaves below the lowest branch and smaller leaves on the upper part. Ray florets are lacking in some individuals of <i>A. oldhamii</i>.</li>

物候

Fl. Nov-Jun.

分布

• 台灣 : northern coast of Taiwan.

引證標本

TAIPEI: Keelung, Faurie 205; Tamura, Shimizu & Kao 20005. ILAN: Suao, Nagasawa s.n. 1907.

參考文獻

• PENG, Ching-I & CHUNG, Kuo-Fang; LI, Hui-Lin, Flora of Taiwan, second edition 4: 859. 1998.  (Fl. Taiwan 2nd edit.)