Chasmanthium latifolium (river oats)

Plate 1 figs. a–h

Chasmanthium latifolium, photographed by Morgan Hay — fig. a Morgan Hay, CC BY 4.0 / 2022-04-29 / obs. 191986517

Chasmanthium latifolium, photographed by Alan Weakley — fig. b Alan Weakley, CC0 1.0 / obs. 181871402

Chasmanthium latifolium, photographed by Emily Summerbell — fig. c Emily Summerbell, CC BY 4.0 / obs. 175143891

Chasmanthium latifolium, photographed by Jody Shugart — fig. d Jody Shugart, CC BY 4.0 / obs. 177488360

Chasmanthium latifolium, photographed by Lauren McLaurin — fig. e Lauren McLaurin, CC BY 4.0 / obs. 172565894

Chasmanthium latifolium, photographed by saltyhiker — fig. f saltyhiker, CC BY 4.0 / obs. 172215147

Chasmanthium latifolium, photographed by Nathan May — fig. g Nathan May, CC BY 4.0 / obs. 174937756

Chasmanthium latifolium, photographed by Reid Hardin — fig. h Reid Hardin, CC BY 4.0 / obs. 171618888

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Flowering n = 70 observations

Flowering observations of Chasmanthium latifolium by month
Month	Observations
Jan	0
Feb	0
Mar	0
Apr	3
May	3
Jun	12
Jul	21
Aug	10
Sep	7
Oct	11
Nov	2
Dec	1

Peak flowering in Jul, from 70 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 1 synonym

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

Uniola latifolia Michx.

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.

We publish what we can source and we say so when we cannot. This page has no care advice, no toxicity claim and no native range, because we do not yet have those from a source we can cite.