Guide to Liverworts of Oregon: Ricciocarpos natans (L.) Corda
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1a plants thallose > 2b chloroplasts numerous > 62b thallus tissue complex > 70a floating aquatic > 71a floating on surface > Ricciocarpos natans
Synonym: None.
Special Status: None.
Recognition: The typical, aquatic form floats on the surface of still water with such plants as Azolla and Lemna. The plants usually consist of half moon shaped thalli with two or three bifurcations. Extending into the water from the lower surface of the thallus are numerous, long, purple scales. There's nothing else like this. Stranded forms left on mud as water recedes, as illustrated here, are quite different in that the thalli are narrower, bifurcate more extensively, and lack the purple ventral scales. They look like a species of Riccia but have air chambers in their thallus and a deep, narrow dorsal groove.
Distribution: On the surface of ponds or river backwaters; widespread at low to middle elevations but not common.
Comments: A curious plant that catches the attention of nature watchers.
Coyote Creek, Lane Co., Oregon. Photo: Bruce Newhouse, 1 August 2012.
Eagle's Rest Trail, Lane Co., Oregon. 25 March 2022.
Eagle's Rest Trail, Lane Co., Oregon. 25 March 2022.
Eagle's Rest Trail, Lane Co., Oregon. 25 March 2022.
(stranded form) Fern Ridge Reservoir, Lane Co., Oregon. DHW m1752
West end of Rooster Rock State Park, Multnomah Co., Oregon. N. Otting field photo, 16 October 2017.
West end of Rooster Rock State Park, Multnomah Co., Oregon. N. Otting field photo, 16 October 2017.
Riccocarpos natans. Distal aspect. Scott Valley, Lake Co., California. Leopold s.n. (UC), SEM W. Doyle.
Riccocarpos natans. Proximal aspect. Scott Valley, Lake Co., California. Leopold s.n. (UC), SEM W. Doyle.
Riccocarpos natans. Side view. Scott Valley, Lake Co., California. Leopold s.n. (UC), SEM W. Doyle.