Description from Flora of China
Pteris interrupta Willdenow, Phytographia, 13. 1794; Aspidium gongylodes Schkuhr; A. unitum (Linnaeus) Swartz var. glabrum Mettenius; A. unitum var. hirsutum Mettenius; Cyclosorus gongylodes (Schkuhr) Link; C. gongylodes var. glaber (Mettenius) Ching; C. gongylodes var. hirsutus (Mettenius) Farwell; Dryopteris gongylodes (Schkuhr) Kuntze; D. gongylodes var. hirsuta (Mettenius) C. Christensen; D. interrupta (Willdenow) Ching; Nephrodium gongylodes (Schkuhr) Schott; Thelypteris gongylodes (Schkuhr) Small; T. interrupta (Willdenow) K. Iwatsuki.
Plants 40-100 cm tall. Rhizomes long creeping, black, including bases of stipes with sparse ovate-lanceolate scales. Fronds distant; stipes 20-60 cm, bases black, distally stramineous; laminae 20-50 × 10-20 cm, bases not narrowed, apices caudate with apical pinna similar to lateral ones; lateral pinnae 10-25 pairs, linear-lanceolate, 5-10 × ca. 1 cm, shortly stalked, bases rounded-truncate, lobed 1/4-1/2 toward costae, apices acuminate; segments 20-30 pairs on middle pinnae, triangular, 3-5 × 2-4 mm, apices pointed; veinlets 6-10 pairs, proximal pair anastomosing, next 0.5-1 pair running to sinus membrane. Laminae somewhat leathery, reddish when dried, subglabrous adaxially, abaxially with acicular hairs and reddish orange sessile spherical glands along veins and several membranous broadly ovate scales along costae. Sori orbicular, medial to submarginal, proximal 1 or 2 pairs of veins sterile; indusia sparsely hairy. Sporangia bearing spherical reddish orange glands on stalks. Spores sparsely minutely echinulate. 2n = 72, 144.
According to recent molecular study by Smith and Cranfill (Amer. Fern J. 92(2): 131-149. 2002), Cyclosorus interruptus is distantly related to other species in this genus but is quite close to Ampelopteris prolifera. This relationship requires further study.
Swamps, wetlands; near sea level to 500 m. Fujian, Guangdong, Guangxi, Hainan, Jiangxi, Taiwan, S Yunnan [throughout tropical and subtropical regions of the world].