Lycopodium squarrosum G. Forster, Fl. Ins. Austr. 86. 1786; Huperzia squarrosa (G. Forster) Trevisan; L. forsteri Poiret, nom. illeg. superfl.; L. pseudosquarrosum Pampanini; L. remoganense Hayata; Plananthus squarrosus (G. Forster) P. Beauvois; Urostachys madagascariensis (Desvaux ex Nessel) Herter; U. squarrosus (G. Forster) Herter; U. squarrosus f. madagascariensis Desvaux ex Nessel.

Lycophytes, large, epiphytic. Stems caespitose, robust, mature branches pendulous, 1 to several times forked, 25-100 cm, main stems 3-7 mm, stem together with leaves 2.5-3 cm wide at middle. Trophophylls lustrous, lanceolate, attached at right angles or slightly angled upward, 1.1-1.5 cm × 1-2 mm, thinly leathery, midrib distinct, base cuneate, decurrent, sessile, margin entire, apex acute. Strobili terminal on branches, slightly thinner than sterile part, columniform. Sporophylls densely arranged, ovate-lanceolate, 8-15 × ca. 0.9 mm, midrib distinct, base cuneate, margin entire, apex acute. Sporangia yellowish, reniform, vertically bisected.

Phlegmariurus squarrosus is the largest species of the genus in China; both branches and sporangia are robust, and its sporophylls are ovate-lanceolate.

Epiphytic on tree trunks in forests or terrestrial; 400-1900 m. NW and W Guangxi, Taiwan, S Xizang, Yunnan [Bangladesh, Bhutan, Cambodia, India, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand; Madagascar, Pacific islands].