Plants 15-25 cm tall. Rhizomes erect, bearing a cluster of thick fleshy roots; roots extending horizontally like stolons, producing a new plant from apical bud. Fronds simple; common stalk 9-15 cm. Sterile lamina sessile, ovate to broadly ovate, 3-6 × 2-3 cm, herbaceous, base ± elongated and rounded, apex acute or obtuse; veins fairly distinct, reticulate. Sporophore arising from base of sterile lamina, 6-9 cm; linear spike 2.5-3 cm. Spore surface obviously subreticulate with fine granules. 2n = 960-1100.
Open shrubby hillsides; 200-3300 m. Fujian, Guizhou, Hainan, Hubei, Sichuan, Taiwan, Yunnan [W India, Indonesia, Japan, Nepal, Philippines, Sri Lanka, Thailand; Australia, North America, Pacific islands (New Zealand)].
Specimens described as Ophioglossum pedunculosum Desvaux in FRPS (2: 9-10. 1959) and some provincial floras (e.g., floras of Anhui, Fujian, Guangdong, Guizhou, Jiangxi, and Yunnan) should be included in O. petiolatum. According to the studies by Clausen (Mem. Torrey Bot. Club 19(2): 1-177. 1938), O. pedunculosum was described as having a lamina with a prominent pale median band, but this character is very different in Chinese specimens. Whether O. pedunculosum is really distributed in China needs further study. Chinnock (Fl. Australia Online: http://www.anbg.gov.au/abrs/online-resources/flora; accessed 18 Jul 2012) includes O. petiolatum within O. reticulatum.