Herbs or subshrubs, procumbent to ascending. Stems well branched, sulcate-striate, glabrous, rarely sparingly puberulent. Leaves obovate to oblanceolate, 3-5×0.7-1.7 cm, apex obtuse to rounded, base gradually narrowed, sessile, irregularly and sparsely dentate, glabrous on both surfaces; upper leaves smaller and narrower. Heads 6-8 mm in diam. when fresh, to 10 mm in diam. when dried, ca. 7 mm long, short pedunculate or sessile, densely congested in terminal corymbs. Involucre ovoid to broadly campanulate, bracts glabrous, 5- or 6-seriate, outer bracts broadly ovate, obtuse to rounded, nearly entire, 2.5-4×2-3 mm; inner bracts linear to lanceolate, acute, nearly entire, 4-5×0.5-1 mm. Receptacle flat, foveolate. Outer florets numerous, corolla filiform, narrowed apically, 3.5-4 mm long, glandular; pappus nearly as long as corolla. Achenes cylindric, reddish brown, with pale ribs, 1-1.4× 0.2-0.3 mm, appressed strigillose and glandular. Central florets 18-22, corolla 4-5 mm long, 5-lobed, lobes triangular, glandular; pappus shorter than corolla; achenes yellowish, cylindric, grooved, 0.8-1.2×0.4-0.5 mm, strigillose. Chromosome number, n = 20 (Peng et al., 1998).

YUNLIN: Santiaolun to Chinhu, Ou 5326; Mailiao, Peng 17134. CHIAYI: Tungshih, Shanliao Village, Peng 13470; Auko, Liao 1705. TAINAN: Chiku, Yang et al. 6504; Peimen, Kao 10862; Hsiaokeliao, Peng 10527; Yenshui, Hong s. n. 1978.

Southern China, Indochina. Taiwan, coastal brackish areas and tidal flats, often associated with mangroves and near graveyards on the southwestern seashore.

Kitamura (1937) first reported P. pteropoda in Taiwan based on a single specimen collected from Mt. Chilaichushan, Hualien. Kitamura's report was accepted by Li (1978), Hsu (1980), Hsu and Lu (1984) and Lai (1991), who listed P. pteropoda as a rare species at high elevations in the central mountain range in eastern Taiwan. A thorough search in the field, study of the relevant literature and examination of abundant herbarium materials have revealed, however, that P. pteropoda is a coastal species confined to southwestern Taiwan.