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Vascular Plants of California
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Epilobium densiflorum

Higher Taxonomy
Family: OnagraceaeView DescriptionDichotomous Key
Habit: Annual to perennial herb (to tree). Leaf: cauline or basal, alternate, opposite, or whorled, generally simple and toothed (to pinnately compound); stipules 0 or generally deciduous. Inflorescence: spike, raceme, panicle, or flowers 1 in axils; bracted. Flower: generally bisexual, generally radial, often opening at either dawn or dusk; hypanthium generally prolonged beyond ovary (measured from ovary tip to sepal base); sepals 4(2--7); petals 4(2--7, rarely 0), often fading darker; stamens 2 × or = sepals in number, anthers 2-chambered, opening lengthwise, pollen interconnected by threads; ovary inferior, chambers generally as many as sepals (sometimes becoming 1), placentas axile or parietal, ovules 1--many per chamber, style 1, stigma 4-lobed (or lobes as many as sepals), club-shaped, spheric, or hemispheric. Fruit: capsule, loculicidal (sometimes berry or indehiscent and nut-like). Seed: sometimes winged or hair-tufted.
Genera In Family: 22 genera, +- 657 species: worldwide, especially western North America; many cultivated (Clarkia, Epilobium, Fuchsia, Oenothera). Note: Gaura moved to Oenothera. Fuchsia magellanica Lam. naturalized in northern California.
eFlora Treatment Author: Warren L. Wagner & Peter C. Hoch, family description, key to genera, treatment of genera by Warren L. Wagner, except as noted
Scientific Editor: Robert W. Patterson, Bruce G. Baldwin.
Genus: EpilobiumView DescriptionDichotomous Key

Habit: Annual to subshrub. Leaf: generally opposite proximally (or clustered in axils), generally +- fine-toothed; veins generally obscure. Inflorescence: generally raceme, bracted. Flower: radial or rarely +- bilateral; sepals 4, erect; petals 4, notched; stamens 8, anthers attached at middle, pollen grains generally shed in 4s, cream-yellow; ovary chambers 4, stigma generally club-like, occasionally 4-lobed. Fruit: straight, cylindric to club-like. Seed: generally in 1 row per chamber, generally with white, deciduous hair-tuft.
Etymology: (Greek: upon pod, from inferior ovary) Note: Incl Boisduvalia, Zauschneria. Most taxa polyploid; many with anthers +- = stigma self-pollinated; many hybrids. Taxa with alternate leaves moved to Chamerion.
eFlora Treatment Author: Peter C. Hoch
Reference: Raven 1976 Ann Missouri Bot Gard 63:326--340; Wagner et al. 2007 Syst Bot Monogr 83:81--95
Epilobium densiflorum (Lindl.) Hoch & P.H. Raven
Habit: Annual 0.5--15 dm, simple or branched distally, peeling proximally, spreading hairy or strigose. Leaf: opposite only near base, +- sessile, 14--85 mm, (narrowly) lanceolate to sublinear; distal leaves hairy. Inflorescence: leafy, +- dense spike, sometimes glandular. Flower: hypanthium 1.3--4 mm; sepals 2--8 mm; petals 3--10 mm, rose-purple to white; stigma head-like to irregularly 4-lobed. Fruit: 4--11 mm, cylindric, pliable, not beaked, dehiscent to base; axis persistent; pedicel 0--2.5 mm. Seed: 1.2--1.6(1.9) mm, netted, glabrous, hair-tuft 0. Chromosomes: 2n=20.
Ecology: Streambanks, outwashes, seasonal moist flats; Elevation: < 2600 m. Bioregional Distribution: CA-FP (exc SCo, ChI), MP; Distribution Outside California: to British Columbia, Montana, Arizona, northern Baja California. Flowering Time: May--Oct Note: Highly variable.
Unabridged Synonyms: Boisduvalia densiflora (Lindl.) S. Watson; Boisduvalia densiflora var. pallescens Suksd.; Boisduvalia densiflora var. salicina (Rydb.) Munz
Jepson eFlora Author: Peter C. Hoch
Reference: Raven 1976 Ann Missouri Bot Gard 63:326--340; Wagner et al. 2007 Syst Bot Monogr 83:81--95
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Epilobium densiflorum

botanical illustration including Epilobium densiflorum

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Citation for this treatment: Peter C. Hoch 2012, Epilobium densiflorum, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on June 21, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on June 21, 2024.

Epilobium densiflorum
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©2008 Neal Kramer
Epilobium densiflorum
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©2005 Keir Morse
Epilobium densiflorum
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©2008 Neal Kramer
Epilobium densiflorum
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©2006 George W. Hartwell
Epilobium densiflorum
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©2009 Barry Breckling

More photos of Epilobium densiflorum
in CalPhotos

Geographic subdivisions for Epilobium densiflorum:
CA-FP (exc SCo, ChI), MP
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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).


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 (fruiting time in some monocot genera).