Terrestrial ferns. Rhizomes short- (not NZ) to long-creeping (NZ), bearing yellow to red multicellular hairs. Fronds monomorphic. Stipes hairy or occasionally spiny (not NZ). Laminae 3–4-pinnate (NZ) or rarely 1–2-pinnate (not NZ), herbaceous (NZ) or coriaceous (not NZ), bearing non-glandular hairs; primary pinnae stalked, lacking basal pinnule-like stipules. Veins free. Sori round (NZ) or broader than long (not NZ), on a slightly raised receptacle, marginal; paraphyses present or absent. Indusia cup-shaped or slightly bivalvate, formed from a true inner indusium and outer modified inrolled lamina flap, attached at base. Spores trilete, tuberculate to verrucate or coarsely ridged or reticulate.
The taxonomy of Dennstaedtia has been revised in America (Tryon 1960; Tryon & Tryon 1982) but is inadequately studied in the Old World. The genus is closely related to, and often difficult to distinguish from, Microlepia. It is also not monophyletic, with two distinct clades identified (Schuettpelz & Pryer 2007; Perrie et al. 2015), one of them closely related to Microlepia. Perrie et al. (2015) also noted that one clade had chromosome numbers based on x = 46 or 47, while the other had counts based on x = 30, 31, 32, 33, or 34.
In New Zealand, Dennstaedtia can be recognised by its creeping rhizomes, highly divided laminae bearing non-glandular hairs, more or less round marginal sori, and cup-shaped or bivalvate indusia.
A genus of about 70 species (PPG 1 2016) in tropical and temperate regions of the Americas, Asia, Australia, and the Pacific (Brownsey 1998); 12 species in the Americas (Tryon 1960; Tryon & Tryon 1982), one in Africa (Roux 2009), eight in China (Yan et al. 2013), 15 in the Philippines (Copeland 1958), 12 in New Guinea (Copeland 1950), one in Australia (Brownsey 1998), and about eight in the Pacific. The Australian species occurs as a casual in New Zealand.
Category | Number |
---|---|
Exotic: Casual | 1 |
Total | 1 |