Orthostichella is a genus of predominantly epiphytic, frequently pendulous mosses of tropical and subtropical American-African distribution. Plants of Orthostichella have creeping primary stems and erect or pendent secondary stems. Its stolons, stems, and branches lack a stem central strand, and its axillary hairs are usually reddish throughout. The secondary stems can be strongly stipitate or non-stipitate throughout; at times both types of secondary stems can be found on the same primary stems. Its branches often end in filiform attenuations or stolons. The stolons, secondary stems, branches, and filiform attenuated branches can be morphologically distinct, but more often they intergrade or abruptly transform from one structure to another. In general the leaves on the branches (and some-times the secondary stems) are spirally ranked, while those on the stolons and primary stems are un-ranked. Most leaves are cuspidate, with distinctive incurved, serrulate upper leaf margins, elongate, smooth, firm-walled leaf cells, and weakly developed, reddish yellow, firm-walled alar cells. The costae in Orthostichella are one of its oddest features. In some species, most leaves are ecostate, but here and there leaves with short double, short single, or long single costae can be found. In other spe-cies, most leaves have a long single or long double costa, but here and there ecostate leaves can be found.

Orthostichella is a dioicous genus and sporophytes are rarely encountered. They are, however, uniform throughout the genus. The setae are elongate-flexuose and variously papillose, roughened above. The genus has ovoid to short-cylindrical capsules, long-rostrate opercula, and mostly hairy, cucullate calyptrae. Orthostichella has a reduced, diplolepideous peristome, with yellowish white ex-ostomes and endostomes that are nearly the same length as the exostome teeth. The more or less lin-ear exostome teeth are lightly horizontally striate on the dorsal (outer) surface at base. The endostome has a low basal membrane with filamentous, narrowly perforate segments; cilia are usually absent. Orthostichella essentially has a neckeroid peristome, but the presence at the base of the exostome teeth of horizontal striae indicates it likely represents a reduced, hypnoid-type peristome.

The genus has long been treated as a subgroup of Pilotrichella (Müll. Hal.) Besch. (Fleischer 1908; Brotherus 1925; Bartram 1949; Florschütz 1964; Walther 1983; Vitt 1984; Spessard-Schueth 1994b; Churchill & Linares 1995; Duarte Bello 1997; Magill & Rooy 1998). Pilotrichella differs from Orthostichella in its larger plant size; absence of stipitate stems; and non-ranked, absolutely ecostate leaves with well-developed alar cells. Sporophytically, Pilotrichella differs from Orthos-tichella in having longer setae and larger (to 64 µm) spores. Although Orthostichella has been placed in the Lembophyllaceae (Buck 1994a, 1994b), a recent revision of the genus (Allen & Magill 2007) considered it better placed in the Neckeraceae by virtue of its stolon/stipe morphology, poorly and variably developed leaf costae, and yellowish white neckeroid peristome. Within the Neckeraceae, the genus is isolated by virtue of its non-complanate stems with leaves that are often arranged in spiral rows.

The name Orthostichella combines the Greek orthos (straight) and stichos (row) with the Latin substantival suffix -ella (diminutive). The name refers to the strongly ranked branch leaves in the genus; they are, however, often in spiral rather than straight rows.