Odorrana graminea, the large odorous frog, inhabits fast-flowing streams in elevated mountainous regions of Southern China and Northern Indochina. It is one of 56 species in the genus Odorrana. Male O. graminea are noted for their ultrasonic call characteristics and are one of three frog species able to detect ultrasonic frequencies (>20 kHz), likely evolved to facilitate communication amidst noisy streams and waterfalls. Studies on O. graminea courtship vocalizations suggest female preference for increased proportion of nonlinear vocal phenomena (NLP). Description Odorrana graminea have a dorsoventrally compressed body with large eyes. Dorsum is green with smooth skin; flanks are brown with yellow marbling and with slight granulations. They are relatively large frogs, particularly the females: females grow to a snout–vent length of , whereas males attain a more modest length of . Apart from size, males differ from females by their smaller digital disks, stronger forearms, larger tympanum, velvety nuptial pads on thumb, and paired gular pouches below jaw articulations. Odorrana graminea can produce ultrasonic calls. This is very rare among non-mammalian vertebrates, but has been shown for the related concave-eared torrent frog Odorrana tormota. However, O. graminea does not have recessed ears, a feature believed to be important for ultrasonic hearing in O. tormota. Exactly how O. graminea detects ultrasound remains yet to be determined. Habitat and distribution Odorrana graminea is found in southern China (from southern Anhui and northern Zhejiang west to extreme southern Gansu, southeastern Sichuan, and southern Yunnan to the border of Vietnam, Laos and Myanmar, although it has not yet been recorded in the latter two countries. Its type locality is the Wuzhi Mountain in Hainan. Until the revision of "Rana livida" in 2003, this frog was considered a synonym of Odorrana livida. The species occurs near fast-flowing rivers and streams in montane (sub-)tropical forests. Taxonomy Odorrana graminea is one of 56 species in the genus Odorrana. All Odorrana frogs live in tropical and subtropical mountainous regions in East and South Asia. The genus is rapidly growing, with over twenty new species documented since 2005. Conservation The conservation status of Odorrana graminea is Least concern according to the International Union for Conservation of Nature. Species in genus Odorrana ranges from “Least Concern” (e.g., Odorrana schmackeri) to “Endangered” (e.g., Odorrana splendida) - with many other species also documenting data deficiency. Habitat loss Rampant deforestation has led to habitat loss and subsequent population decrease for many amphibians.