Physematium Kaulf.

Ponce, M. Mónica, Gorrer, Daniel A. & Arana, Marcelo D., 2025, Hidden and neglected taxa inside a collective taxon: taxonomic revision of Woodsiaceae in the Southern Cone of South America, Willdenowia 55 (1), pp. 29-49 : 32-34

Physematium Kaulf. in Flora 12: 341. 1829. – Type: Physematium molle Kaulf. in Flora 12: 341. 1829.

Morphological description — Plants small to mediumsized (up to 40 cm tall); usually lithophytic. Roots blackish, wiry, inserted radially. Rhizomes usually long-creeping or erect, bearing scales at apex, non-clathrate, brown to blackish-brown, centre usually sclerotic, margin entire to toothed. Fronds clustered, monomorphic, deciduous or sometimes evergreen; stipes stramineous or dark purple throughout, or proximally darkened, usually covered with scales and septate hairs, non-articulate, rigid or brittle. Lamina pinnate-pinnatifid or pinnate-pinnatisect to 2-pinnate-pinnatifid, elliptic-lanceolate to narrowly lanceolate, membranous to subcoriaceous, glabrous or frequently covered with articulate hairs, sometimes with glandular hairs or capitate glands. Veins free, pinnate, usually ending in enlarged hydathodes. Sori dorsal along veins, subterminal or terminal, round, indusiate; soral receptacle flat; indusia inferior, globose, sacciform or saucer-shaped to cup-shaped, margin ciliate, or indusia developed into strap-shaped or filamentous segments. Spores ellipsoid or somewhat spheric, monolete, nonchlorophyllous, yellowish, tan or brown, perispore fold- ed, cristate or echinate. x = 38.

Distribution — A genus with three subgenera ( Physematium subg. Cheilanthopsis (Hieron.) Li Bing Zhang & al., P. subg. Physematium and P. subg. Woodsiopsis (Shmakov) Li Bing Zhang & al.) and c. 30 species distributed in Asia, Africa, Madagascar and America, with at least six species in South America, four in the Southern Cone, with the highest diversity in Andean and Pampean mountainous habitats, reaching its southern distribution limit in the highlands of Río Negro, Argentina. All species inhabiting the Southern Cone belong to P. subg. Physematium .

Remarks — In Physematium montevidense , the germination pattern of the gametophyte corresponds to the Vittaria - type and the development is Aspidium - type. Gametangia appeared 30–40 days after spore germination. The sporophytes emerged near 3 months after spore sowing ( Martinenco & al. 2023).