174. Filago Linnaeus, Sp. Pl. 2: 927, 1199, [add. post indicem]. 1753.
絮菊属 xu ju shu
Authors: Yousheng Chen & Randall J. Bayer
Herbs, annual. Stems with fibers in phloem, without resin canals, without pericyclic cambium. Leaves alternate, sessile, tomentose, eglandular. Capitula heterogamous, disciform, few together, surrounded by a ray of leaves. Phyllaries few seriate, cartilaginous or apically minutely papery, monomorphic, monochromous, brownish, transparent, not enclosing florets; stereome entire. Receptacles filiform, fragile; paleae subtending outer female florets, 3-5-seriate, imbricate, scarious. Female florets purple, filiform, outnumbering disk florets. Disk florets bisexual, or functionally male; corolla purple; corolla lobes 4, erect; veins ending below lobes. Anthers ecalcarate, with short tails; endothecial tissue polarized; apical appendage flat, as wide as thecae. Achenes brown, monomorphic, terete to compressed, cylindric to obovoid, with 2 vascular bundles, sparsely hairy with short, clavate, myxogenic twin hairs; epidermis smooth. Pappus monomorphic, of free scabrid capillary bristles in 1 row, basally with patent cilia; apical cells acute. x = 9, 13, 14.
About 46 species: N Africa, SW Asia, Atlantic islands, Europe; two species in China.
