Directory       News       Site Map       Home
         
    Jepson eFlora: Taxon page
Key to families | Table of families and genera

Previous taxon Indexes to all accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Previous taxon

HYDROCHARITACEAE WATERWEED FAMILY

Robert F. Thorne, C. Barre Hellquist & Robert R. Haynes

Annual, perennial herb, aquatic, freshwater or marine, glabrous or hairy; monoecious, dioecious, or flowers bisexual. Leaf: basal, alternate, opposite, or whorled, generally sessile, generally ± sheathing at base. Inflorescence: axillary, terminal, or scapose, cyme or flowers 1, subtended by ± sheathing, entire or lobed bract; staminate flowers sometimes deciduous, free-floating. Flower: generally radial; perianth 0 or tube 0 or elongate, peduncle-like in flower; sepals (0)3(4), green; petals (0)3(4), white or not; stamens (0)2–many, generally in 1+ series; ovary inferior, chamber 1 or falsely 6–9, placentas parietal, ovules 1–many, style lobes generally 3, linear, lobed or notched. Fruit: achene or berry-like and dehiscing irregularly, linear to spheric, submersed.
± 17 genera, ± 130 species: worldwide; some cultivated for aquaria, others noxious weeds. [Haynes 2000 FNANM 22:26–38] Ottelia alismoides (L.) Pers. is a possibly extirpated alien. —Scientific Editor: Thomas J. Rosatti.
Unabridged references: [Les, D. H. [et al. 2006], Moody, M. L., & Soros, C. L. 2006. A reappraisal of phylogenetic relationships in the monocotyledon family Hydrocharitaceae (Alismatidae). Pp. 211–230, in Columbus, J. T., Friar, E. A., Porter, J. M., Prince, L. M., & Simpson, M. G. (eds), Monocots: Comparative Biology and Evolution. Excluding Poales. Rancho Santa Ana Botanical Garden, Claremont, Ca. [Aliso 22: 211–230.]; Tanaka, N., Uehara, K., & Murata, J. 2004. Correlation between pollen morphology and pollination mechanisms in the Hydrocharitaceae. J. Plant Res. 117:265–276]

Key to Hydrocharitaceae

HYDRILLA

1 sp. (Greek: in water)

H. verticillata (L. f.) Royle
NATURALIZED
Perennial herb, rooting at nodes, submersed; dioecious. Stem: tuber-like; erect stems elongate, much-branched. Leaf: generally 4–8 per node, sessile, 1–2 cm, 1.5–2 mm wide, oblong, coarsely serrate, midrib prickled abaxially or not, tip generally sharp-pointed. Staminate inflorescence: flower 1, bract at base of elongate perianth tube, spheric. Pistillate inflorescence: flower 1, bract at base of elongate perianth tube, ± cylindric. Staminate flower: deciduous, free-floating; perianth parts 6 in 2 whorls, 3–5 mm; stamens 3. Pistillate flower: persistent, floating; perianth parts 6 in 2 whorls, 3–5 mm; stigmas 3. Fruit: 5–6 mm, ± fusiform.
2n=32. Canals, ponds, lakes; < 200 m. Inner North Coast Ranges, n&c Sierra Nevada Foothills, Sacramento Valley, South Coast, Desert; southeastern and eastern United States, Central America; native to Eurasia, Australia. Jun–Aug {Noxious weed} [Online Interchange]

Previous taxon: Hydrilla
Next taxon: Limnobium

Contact/Feedback

Name search

Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on Nov 23 2014
Citation for this treatment: [Author of taxon treatment] 2013. Hydrilla, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=28595, accessed on Nov 23 2014

Copyright © 2014 Regents of the University of California
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.


Geographic subdivisions indicated for the distribution of Hydrilla verticillata Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

 

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.