Compilation
Psilotrichum sericeum

Erect, prostrate or ascending annual, c. 0.3–1 m tall, much branched at least in the lower half, the lowest internodes of at least the lower branches very divergent. Stem and branches striate, subglabrous with sparse soft hairs to densely furnished with short soft hairs and long multicellular hairs (which occur around the nodes even when absent elsewhere). Main stem and branch leaves opposite, cordate-ovate to broadly ovate, rarely cordate-lanceolate, 1.3–7 x 0.7–5.2 cm, obtuse to acuminate, the lower distinctly petiolate, the upper reducing and sessile; indumentum very variable, from green on both surfaces with the upper surface thinly and the lower moderately appressed-pilose to moderately appressed-pilose above and silvery-sericeous beneath. Inflorescence a large open panicle of opposite, axillary, simple or branched spikes each with a fine zigzag glabrous rhachis. Flowers sessile. Tepals green: outer 2 lanceolate, 2–3 mm, the 3 nerves equally strong, glabrous or usually with the nerves or sometimes the whole surface white-pilose, narrowly hyaline-margined; inner 2 pilose only along the midrib, broadly hyaline-margined, the lateral nerves less strong; middle tepal with one side as in the outer and one as in the inner tepals. Style c. 0.5 mm. Capsule ovoid, c. 1.75–2 mm.