Dumortiera hirsuta
This species is recognized by the large and flat, dark green thalli; without air pores and air chambers; margins of male and female receptacles with numerous hairs.
Thalli dark-green, broad, dichotomously branched, without air chambers, pores, and ventral scales; rhizoids mostly smooth and sparsely tuberculate; midrib well-develop; margins crispate-crenulate; epidermal cells smaller than inner cells; oil body cells present on the epidermal layer, brownish, compound, spherical. Male receptacles on the apex of thallus with hyaline scales; female receptacles with long stalk, disk surrounded by marginal bristles.
Africa, Europe, America, China, Hong Kong, Japan, Sri Lanka, Cambodia, Laos, Vietnam, Indonesia, Java, Philippines, and Thailand (Arnell, 1963; So, 1995; Lai et al., 2008; Söderström, 2010).
On soil and rocks near streams, in primary, evergreen, seasonal, hardwood forest; granite bedrock, Ru See Cave, c. 1,250 m elevation; Mahidol Falls, c. 1,058 m elevation; on soils and rocks, in mixed evergreen + deciduous seasonal, hardwood forest, Sirindhorn Observatory area, c. 850 m elevation; Pha Laht Falls, c. 750 m elevation; Montahtahn Falls, c. 746 m elevation; on soil and rocks in deciduous dipterocarp-oak forest, Daht Mawk Falls, c. 544 m elevation; Mae Sa Falls, c. 417 m elevation.