Mesanthemum radicans Körn.

Robust tussocky perennial from a short or elongating rhizome.. Leaves clustered at the rhizome tip, 12–50 cm. long, (5–)10–15 mm. wide, scattered-pilose or glabrescent, rarely hirsute with patent hairs.. Scapes tough, 30–60 cm. high; sheaths usually pilose, the limb tomentellous within.. Capitulum creamy-white, flat-topped with a campanulate involucre, 10–15 mm. diameter; involucral bracts coriaceous with thinner margins, straw-coloured with greenish tips, patchily appressed-sericeous, outermost 3.0–3.6 mm. long, broadly ovate, rounded, innermost extending shortly beyond the floral disc, oblong, obtuse or subacute, white-hairy on the inner face; floral bracts capillary with a white-pilose subulate tip; receptacular hairs dark grey; flowers 2.2–2.8 mm. long.. Male flowers: sepals free, pallid, broadly oblong, tips truncate and white-ciliate.. Female flowers: sepals pallid, half as long to subequalling the petals, ovate-oblong, truncate-denticulate, glabrous or the tips white-ciliate in a central tuft; petals free near the base, central connate portion villous with long grey hairs outside and within, tips densely pilose with short white hairs.. Fig. 5.

In swamps or streams