37. Cyclosorus aridus (D. Don) Ching, Bull. Fan Mem. Inst. Biol., Bot. 8: 194. 1938.
干旱毛蕨 gan han mao jue
Aspidium aridum D. Don, Prodr. Fl. Nepal. 4. 1825; Christella arida (D. Don) Holttum; Cyclosorus acutissimus Ching ex K. H. Shing & J. F. Cheng; C. serrifer Ching ex K. H. Shing; Dryopteris arida (D. Don) Kuntze; Nephrodium aridum (D. Don) J. Smith; Thelypteris arida (D. Don) C. V. Morton.
Plants (30-)50-100(-150) cm tall. Rhizomes long creeping, including stipe bases with sparse brown lanceolate scales. Fronds distant; stipes 10-35 cm; laminae (20-)40-80(-120) × (10-)15-35 cm, bases abruptly or gradually narrowed, apices caudate to acuminate; pinnae 15-40 pairs, proximal 2-10 pairs shortened; middle pinnae linear-lanceolate, (5-)10-18 × 1-2 cm, bases truncate, lobed to 1/3 toward costae or sometimes only dentate, apices long acuminate; segments 20-40 pairs on middle pinnae, triangular, 1-3 × ca. 3 mm, entire, acute or pointed at apices; veinlets 6-12 pairs, much oblique, proximal 2 or 3 pairs anastomosing, next 1 or 2 pairs running to sinus membrane. Laminae papery to somewhat leathery, brownish green or yellowish green when dried, adaxially subglabrous except for several short acicular hairs along costae, abaxial surface with short acicular hairs along costae and veins, also with yellow or orange clavate glands along veins. Sori orbicular, medial; indusia glandular, sometimes hairy. Sporangia bearing yellow or orange clavate glands on stalks. Spore with long wings or ridged folds. 2n = 72.
Wet or semi-open places, usually among tall grasses; near sea level to 2500 m. S Anhui, Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, SE Xizang, Yunnan, Zhejiang [Bhutan, India, Indonesia, Kashmir, Malesia, Nepal, Philippines, Vietnam; Australia, Pacific islands].
K. H. Shing mentioned in FRPS (4(1): 278. 1999) that Cyclosorus subaridus represented a small form of C. aridus. However, after careful examination, we found that C. subaridus resembles the type of C. jaculosus, and it is here included in synonymy of that species.
The type of Cyclosorus medogensis Ching & S. K. Wu (Fl. Xizang. 1: 171. 1983) resembles this species but differs by deeper lobed segments and less anastomosing veins. Its type has quite rare fertile sori. Only one gathering (the type) has been collected. This taxon might be a hybrid.
The type of Cyclosorus omeigensis Ching (Bull. Fan Mem. Inst. Biol., n.s., 1: 289. 1949; Christella omeigensis (Ching) Holttum; Thelypteris omeigensis (Ching) C. F. Reed) has features intermediate between Cyclosorus aridus and Pronephrium penangianum. Only one gathering (the type) lacking fertile sori has been collected. This taxon might be a hybrid.
The type of Cyclosorus pseudoaridus Ching ex K. H. Shing (FRPS 4(1): 278. 1999) has features intermediate between C. aridus and C. acuminatus. Only one gathering (the type) with rare fertile sori has been collected. This taxon might be a hybrid.