Egeria densa

Higher Taxonomy

Family: Hydrocharitaceae

Common Name: WATERWEED FAMILY
Habit: 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.
Genera In Family: +- 17 genera, +- 130 species: worldwide; some cultivated for aquaria, others noxious weeds. Note: Ottelia alismoides (L.) Pers. is a possibly extirpated alien.
eFlora Treatment Author: Robert F. Thorne, C. Barre Hellquist & Robert R. Haynes
Scientific Editor: Thomas J. Rosatti.

Genus: Egeria

View Description

Common Name: BRAZILIAN WATERWEED
Habit: Perennial herb, submersed, rooted in mud; dioecious. Stem: slender, branched or not. Leaf: opposite below, crowded and in whorls of 3--6 above, sessile, finely to coarsely serrate. Staminate Inflorescence: axillary, sessile; flowers 2--4(5), 1 open at a time; bract slender. Pistillate Inflorescence: [axillary, sessile; flower 1; bract slender, +- tubular]. Staminate Flower: floating; pedicel elongate, peduncle-like, persistent on pl; stamens 9. Pistillate Flower: [floating; perianth tube elongate, peduncle-like; stigmas 3, 3--4-lobed].
Etymology: (Latin: mythical water nymph) Note: Only staminate plants observed outside native range. Egeria najas Planch. expected but not yet found.

Egeria densa Planch.

NATURALIZED
Stem: 2--3 mm thick. Leaf: 1.2--4 cm, 2--5 mm wide, recurved, narrowly oblong, finely serrate. Staminate Flower: pedicel <= 8 cm; petals 8--10 mm, white, +- round. Pistillate Flower: [as staminate; petals 6--7 mm]. Chromosomes: 2n=46.
Ecology: Streams, ponds, sloughs; Elevation: < 2200 m. Bioregional Distribution: SNF, GV, SnFrB, SnJt, GB; Distribution Outside California: to eastern United States; Europe; native to South America. Flowering Time: Jul--Aug Note: Staminate plants widely cultivated for aquaria.
Synonyms: Elodea densa (Planch.) Casp.
Jepson eFlora Author: Robert F. Thorne, C. Barre Hellquist & Robert R. Haynes
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
Noxious Weed listed on the CDFA Weed Pest Ratings table
View the CDFA Pest Rating page for Egeria densa
Weed listed by Cal-IPC

Previous taxon: Egeria
Next taxon: Elodea

Botanical illustration including Egeria densa

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Citation for this treatment: Robert F. Thorne, C. Barre Hellquist & Robert R. Haynes 2012, Egeria densa, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=23849, accessed on April 25, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 25, 2024.

Egeria densa

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Geographic subdivisions for Egeria densa: SNF, GV, SnFrB, SnJt, GB	MAP CONTROLS 1. You can change the display of the base map layer control box in the upper right-hand corner. 2. County and Jepson Region polygons can be turned off and on using the check boxes.

(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).	Data provided by the participants of the Consortium of California Herbaria. MAP LEGEND View all CCH records All markers link to CCH specimen records. The original determination is shown in the popup window. Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. READ ABOUT YELLOW FLAGS CCH collections by month Duplicates counted once; synonyms included. Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA. Blue line denotes eFlora flowering time (fruiting time in some monocot genera).