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American Pillwort
Pilularia americana
About American Pillwort (Pilularia americana) 0 Nurseries Carry This Plant The American pillwort, Pilularia americana A. Braun is an unusual species of fern. The fronds essentially consist of the stems only, any form of flattened laminae having been lost. It is in the aquatic fern family Marsileaceae, and is related to the water clovers and also to Azolla and Salvinia. The range of the American pillwort is well-established throughout much of California and south-central Oregon. However, mostly only local occurrences have been found elsewhere in eastern North America. It is uncertain whether this reflects a genuinely sporadic occurrence, or whether this is a reflection of the fact that this is a small, grasslike, extremely easily overlooked plant. Close examination is often necessary to ascertain that this is a Pilularia. The species also occurs through Central and South America, although scientific investigation may confirm those plants to be a separate species, P. mandoni A. Braun. Recent research has determined that the North American plants normally assigned to P. americana are actually two different (cryptic) species. The plants in most of the United States range are true americana, while plants in southernmost California and Mexico are different, and are in fact very close genetically to the Australian and New Zealand species, Pilularia novae-hollandiae, and may possibly be eventually regarded as part of that species. This plant is easily grown given a suitable habitat and kept uncrowded. The pillwort also may die out for drier or colder parts of the season, regenerating the next year from the sporocarps. While it is in the aquatic fern group, it prefers to be emergent (in shallow water, with fronds emerging into the air) or growing completely emersed (fronds completely out of water), though preferring to be rooted in wet mud.
Plant Description
Plant Type
Plant Type

Landscaping Information
Natural Setting
Annual Precipitation: 7.4" - 60.4", Summer Precipitation: 0.17" - 2.49", Coldest Month: 23.0" - 55.4", Hottest Month: 41.4" - 80.9", Humidity: 0.56" - 29.16", Elevation: -3" - 12337"

Sources include: Wikipedia. All text shown in the "About" section of these pages is available under the Creative Commons Attribution-ShareAlike License. Plant observation data provided by the participants of the California Consortia of Herbaria, Sunset information provided by Jepson Flora Project. Propogation from seed information provided by the Santa Barbara Botanical Garden from "Seed Propagation of Native California Plants" by Dara E. Emery. Sources of plant photos include CalPhotos, Wikimedia Commons, and independent plant photographers who have agreed to share their images with Calscape. Other general sources of information include Calflora, CNPS Manual of Vegetation Online, Jepson Flora Project, Las Pilitas, Theodore Payne, Tree of Life, The Xerces Society, and information provided by CNPS volunteer editors, with special thanks to Don Rideout. Climate data used in creation of plant range maps is from PRISM Climate Group, Oregon State University, using 30 year (1981-2010) annual "normals" at an 800 meter spatial resolution.

Links:   Jepson eFlora Taxon Page  CalPhotos  Wikipedia  Calflora

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