Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
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Elizabeth McClintock

Annual, perennial herb, shrubs, trees
Stem angled or cylindric
Leaves simple, entire, generally opposite, sometimes alternate or whorled
Inflorescence: raceme, spike, or panicle, terminal, or axillary clusters with 1–several flowers
Flower bisexual, generally radial; hypanthium cylindric to bell-shaped, generally membranous, persistent in fruit; sepals 4–6, generally persistent, appendages 3–5 or 0, alternate sepals; petals, stamens inserted on inner hypanthium; petals 4–6 or 0, alternate sepals, deciduous; stamens generally = or 2 X petals, included or exserted; ovary superior, chambers 2–6, style generally slender, stigma head-like
Fruit: capsule, opening by valves from top, splitting sometimes irregular or 0
Seeds 3–many
Genera in family: ± 25 genera, 450 species: temp, tropical, generally in wet habitats. Some ornamental or cultivated for medicine, dyes
Reference: [Graham 1964 J Arnold Arbor 45:235–250]


Stem prostrate to erect, glabrous
Leaves opposite, 4-ranked, sessile, linear to oblanceolate, generally with basal ear-like lobes
Inflorescence: cluster, axillary; flowers 3–10; bractlets 2, inconspicuous
Flower radial; hypanthium bell- to urn-shaped, ± spheric in fruit; sepals 4, appendages < or ± = sepals, thick, horn-like; petals (0)4; stamens 4(8), included or exserted
Fruit ± spheric, irregularly dehiscent
Seeds many, ± 1 mm
Species in genus: ± 25 species: temp, tropical
Etymology: (Paul Ammann, Germany, 1634–1691)
Reference: [Howell 1985 Wasmann J Biol 43:72–74]


A. robusta Heer & Regel

Stem decumbent to erect, 1–10 dm, solitary or branched
Leaf 1.5–8 cm, 5–15 mm wide, generally linear-lanceolate
Inflorescence compact; flowers 1–3(5), sessile
Flower: hypanthium urn-shaped, often 4-ridged; appendages ± = sepals in fruit; petals 3–4(8) mm, obovate, pale lavender; stamens 4(5–12), exserted in flower, anthers pale yellow
Fruit 4–6 mm diam
Chromosomes: n=17
Ecology: Wet places, drying pond and ditch margins
Elevation: < 500 m.
Bioregional distribution: North Coast Ranges, s Sierra Nevada Foothills, Great Central Valley, Central Western California, South Coast, s Channel Islands (Santa Catalina Island), Sonoran Desert
Distribution outside California: to c US, Mexico
Flowering time: Jun–Aug
Synonyms: A. coccinea Rottb. misapplied

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bioregional map for AMMANNIA%20robusta being generated
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).

Retrieve Jepson Interchange Index to Plant Names entry for Ammannia robusta
Retrieve dichotomous key for Ammannia
Overlay Consortium of California Herbaria specimen data by county on this map
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