Jepson eFlora: Taxon page
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Elatine ambigua

Higher Taxonomy
Family: ElatinaceaeView DescriptionDichotomous Key

Habit: Annual, short-lived perennial herb, in or near water; roots fibrous, from taproot or not, generally from lower leaf axils also. Stem: generally soft. Leaf: simple, opposite, +- 4-ranked; stipules scarious. Inflorescence: flowers in upper axils, 1 or few in clusters. Flower: small, inconspicuous, radial, bisexual; sepals, petals 2--5, equal in number, generally free; ovary spheric, styles 3--5, short. Fruit: capsule, septicidal, +- spheric, ovoid, or depressed-ovoid, walls thin; chambers 2--5, each several to many-seeded. Seed: small; surface net-like or glossy.
Genera In Family: 2 genera, 50 species: +- worldwide.
eFlora Treatment Author: Gordon C. Tucker & Evanielis U. Grissom
Scientific Editor: Thomas J. Rosatti.
Genus: ElatineView DescriptionDichotomous Key

Common Name: WATERWORT
Stem: Erect underwater, +- prostrate on wet ground, branched or not; base not woody. Leaf: petiole < 1/3 blade, flat, +- blade-like; blades narrow-elliptic to +- round, +- entire, bases wedge-shaped to +- round, tips round. Inflorescence: flowers 1(2) per node. Flower: sepals, petals wide-elliptic, membranous; sepals pale green; petals pale green-white; stamens (1) 3, 6, 8, filaments 1/2 × to +- equal petals, anthers wide-ovoid; styles 3--4. Fruit: +- spheric or depressed-ovoid; chambers 3--4, each 3--15-seeded; pedicel generally +- 0. Seed: +- visible through fruit wall, elliptic, straight or curved, brown to yellow-brown; surface net-like due to ridges between +- linear rows of pits.
Species In Genus: +- 25 species: worldwide. Etymology: (Greek: fir tree, from a European species that suggests such a plant in miniature) Note: At least 20× magnification needed for pits on seeds.

Elatine ambigua Wight
Stem: +- erect, 1--8 cm. Leaf: lanceolate to oblong-elliptic; petiole 1/4 blade. Inflorescence: flowers 1 per node. Flower: sepals 3, +- equal; petals 3, equal, +- > sepals. Fruit: chambers 3; pedicel turned to 1 side, 1/4--1/2 fruit length. Seed: narrow-oblong, curved 15--30°; pits +- 20 per row, wider than long.
Ecology: Vernal pools, wet places; Elevation: 10--100 m. Bioregional Distribution: GV; Distribution Outside California: native to eastern and southern Asia. Flowering Time: Jun--Aug
Unabridged Note: Given habitats, elevation > 100 m unlikely.
eFlora Treatment Author: Gordon C. Tucker & Evanielis U. Grissom
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Citation for this treatment: Gordon C. Tucker & Evanielis U. Grissom 2016. Elatine ambigua, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 26, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on October 26, 2016.

Geographic subdivisions for Elatine ambigua:
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

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