In Peninsular Malaysia, the genusTectaria has been treated as a member of either the Dennstaedtiaceae (Holttum 1954, 1991), Aspidiaceae (Piggott 1988) or Dryopteridaceae (Turner 1995; Parris & Latiff 1997). However according to the most recent molecular phylogenetic classification (Smith et al. 2006; Parris 2010), Tectariabelongs to the family Tectariaceae.

Tectaria is a pantropic genus with c. 210 species. In Malesia, almost all its species are terrestrial forest plants, but some occur as rheopyhtes or only grow on rocks or are confined to limestone areas (Holttum 1991).

There are about 32 species of Tectaria in Peninsular Malaysia (Turner 1995; Parris & Latiff 1997). In general, Tectaria species are characterized by their fronds which range from simple to amply divided; the more-or-less anastomosing veins; and the sori that are positioned at the ends of free veins or on connected veins. The sori are usually round and indusiate, but sometimes are spreading and without indusia.

Tectaria siifolia (Willd.) Copel. is distributed throughout Malesia and is quite local in occurrence (Holttum 1991). In Peninsular Malaysia, it was previously recorded only from Perak and Pahang, often near limestone or sometimes as a terrestrial fern. However, during our fieldtrip to Gua Teja in Kelantan in 2009, this species was also discovered on the limestone there.

Tectaria siifolia has a short-creeping to sub-erect rhizome. The rhizome is covered by narrow, stiff and dark brown scales. The stipes are purple to chestnut-coloured towards the base and may reach up to 30 cm long in sterile fronds, or up to 50 cm long in the fertile fronds. The lamina is three or five-foliolate. It is thinly coriaceous with a glabrous surface, except for the more-or-less hairy costae beneath and the densely hairy rachis covered by very short pale hairs. The terminal pinnae are about 17 × 7.5 cm in sterile fronds or 7.5 × 3 cm in fertile fronds. In the trifoliate fronds, the terminal pinnae are often ovate with a rounded base and a short acuminate apex.

However, in the five-foliolate fronds, the terminal pinnae are usually elliptical with a narrow cuneate base. The lateral pinnae are about 15 × 6.5 cm in sterile fronds or 6.5 × 2.5 cm in fertile fronds. They are sessile, unequal at the base, broadly rounded on the basiscopic side but narrower on the acroscopic side, with entire margin and a caudate-acuminate apex. Vegetative buds, which are often found in the axils of these lateral pinnae and the great differences in size between the sterile and fertile fronds are characterisitics of the species. The venation of the sterile fronds consists of fairly regular cross-veins which enclose two-rows of areoles with included free veinlets, while in the fertile fronds, the venation is made up of fewer areoles. The sori are arranged in two fairly regular rows between each pair of main lateral veins and are quite large. The indusia are thin and easily detach and are shed at an early stage.