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This page is based on the 1993 Jepson Manual.
Please see the Jepson eFlora for up-to-date information about California vascular plants. |
| Jepson Flora Project: Jepson Interchange |
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TREATMENT FROM THE JEPSON MANUAL |
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Jepson Interchange (more information) |
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©Copyright 1993 by the Regents of the University of California
Print edition is available from the University of California Press |
| The second edition of The Jepson Manual (2012) is available from the University of California Press | |
| See also the Jepson eFlora, which parallels the Second Edition |
Perennial, floating aquatics, small, clonal, in dense populations; new plants produced in budding pouch at base or along margins; may overwinter on bottom as dense, rootless, starch-filled daughter plant (winter bud); roots 0many
Plant body 0.410 mm, flat and tongue-shaped to spheric
Flower 1, rarely seen, minute, appearing like 23 unisexual flowers, often sheathed by minute membrane; perianth 0; stamens 12; pistil 1, simple, maturing before stamens
Fruit achene-like, sometimes winged
Seeds 13, smooth or ribbed. Spp. best separated by chemistry and fruit; clones vary; magnification, backlighting generally needed to identify vegetative plants
Genera in family: 4 genera, 34 species: worldwide; ornamental in pools, aquaria
Reference: [Landolt 1986 Veröff Geobot Inst ETH Stiftung Rübel Zürich 71]Horticultural information: TRY.
Plants generally in unequal pairs; roots 0
Plant body 0.41.3 mm, nearly spheric to ± cylindric, floating on or partially below water surface; veins 0; budding pouch funnel-shaped; winter buds often produced
Flower produced in cavity on upper surface; sheathing membrane 0; stamen 1; pistil 1
Seed smooth
Species in genus: 9 species: worldwide, especially temp, tropical
Etymology: (J.F. Wolff, German botanist and physician, 17781806)
Reference: [Armstrong & Thorne 1984 Madroño 31:172179]
CA species may be distinguished by size and shape with > 10X magnification.
| Native |
Plant body 0.40.8 mm, longer than wide, sometimes ± cylindric, transparent green; upper surface with 110 stomates, barely rounded throughout, sometimes darker green, only central portion floating above water; tip round; budding pouch generally with collar of long cells at junction with daughter plant
Ecology: Ponds of hot interior valleys
Elevation: < 200 m.
Bioregional distribution: Sierra Nevada Foothills, San Joaquin Valley, South Coast
Distribution outside California: worldwide, especially tropical
Synonyms: W. cylindracea Hegelm
Smallest of all known angiosperms.
| YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps). |
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