Jepson eFlora: Taxon page
Vascular Plants of California
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Ammannia robusta

Higher Taxonomy
Family: LythraceaeView DescriptionDichotomous Key
Habit: Annual, perennial herb, shrub, tree. Stem: 4-angled or cylindric. Leaf: simple, entire, generally opposite, 4-ranked (alternate, whorled). Inflorescence: flowers terminal or in axils of upper leaves or leaf-like bracts, 1 or in +- dense cymes or along short shoots, sessile or not, subtended by [0]2 bractlets. Flower: bisexual, generally radial; hypanthium bell-shaped to cylindric, membranous or leathery, persistent in fruit; sepals appearing as hypanthium lobes, 4--9, epicalyx lobes alternate sepals or 0; petals, stamens inserted on inner hypanthium; petals 4--6 or 0, alternate sepals, crinkled, deciduous; stamens generally = or 2 × sepals, included or exserted; ovary generally superior, chambers 2--6[many], style generally slender, stigma head-like. Fruit: dry capsule or leathery berry, dehiscent into 2--4 valves or irregularly. Seed: 3--many.
Genera In Family: +- 28 genera, 600 species: temperate, tropics, generally in wet habitats. Some ornamental or cultivated for medicine, dyes. Note: "Epicalyx lobes" (lobes on calyx) formerly called "appendages," "hypanthium" in Lythraceae (and Onagraceae) including receptacle, sometimes called "flower cup" or "flower tube". Punicaceae (Punica) included here.
eFlora Treatment Author: Shirley A. Graham
Scientific Editor: Thomas J. Rosatti.
Genus: AmmanniaView DescriptionDichotomous Key

Habit: Annual. Stem: prostrate to erect, branched or not, glabrous. Leaf: opposite, sessile, linear to lanceolate [oblanceolate], with basal ear-like lobes. Inflorescence: axillary 1--5(14)-flowered cymes. Flower: radial, hypanthium bell- to urn-shaped, 4--8-ribbed; sepals 4, epicalyx lobes <= sepals, horn-like, thick; petals (0)4, obovate; stamens 4(5--12), exserted (included); style long, slender [short, stocky]. Fruit: capsule, +- spheric, wall smooth, not striate at 10×, thin, dry, splitting irregularly. Seed: many, +- 1 mm.
Species In Genus: +- 25 species: temperate, tropics. Etymology: (Paul Ammann, 1634--1691, director of medical garden, University of Leipzig, author of flora of Leipzig area, 1675)
Reference: [Graham et al. 2011 Bot J Linn Soc 166:1--19]
Ammannia robusta Heer & Regel
Stem: 1--10 dm. Leaf: 1.5--8 cm, 5--15 mm wide. Inflorescence: 1--3(5)-flowered. Flower: hypanthium urn-shaped; petals 2--4 mm; stamens 4(5--12), anthers pale yellow. Chromosomes: n=17.
Ecology: Wet places, drying ponds, ditch margins; Elevation: < 500 m. Bioregional Distribution: NCoR, s SNF, GV, CW, SCo, s ChI (Santa Catalina Island), D; Distribution Outside California: to Great Lakes, Louisiana, South America. Flowering Time: Jun--Aug
Synonyms: Ammannia coccinea Rottb. subsp. robusta (Heer & Regel) Koehne
Jepson eFlora Author: Shirley A. Graham
Reference: [Graham et al. 2011 Bot J Linn Soc 166:1--19]
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Botanical illustration including Ammannia robusta

botanical illustration including Ammannia robusta


Citation for this treatment: Shirley A. Graham 2012, Ammannia robusta, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on December 05, 2019.

Citation for the whole project: Jepson Flora Project (eds.) 2019, Jepson eFlora,, accessed on December 05, 2019.

Ammannia robusta
click for enlargement
© 2015 Neal Kramer
Ammannia robusta
click for enlargement
© 2018 Neal Kramer
Ammannia robusta
click for enlargement
© 2015 Chris Winchell
Ammannia robusta
click for enlargement
© 2018 Neal Kramer
Ammannia robusta
click for enlargement
© 2013 Neal Kramer
Ammannia robusta
click for enlargement
© 2015 Chris Winchell

More photos of Ammannia robusta in CalPhotos

Geographic subdivisions for Ammannia robusta:
NCoR, s SNF, GV, CW, SCo, s ChI (Santa Catalina Island), D
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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.
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.

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.