Jepson eFlora: Taxon page
Vascular Plants of California
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Geranium core-core

Higher Taxonomy
Family: GeraniaceaeView DescriptionDichotomous Key
Habit: Annual, perennial herb, or +- woody, generally glandular-hairy. Leaf: simple to compound, basal and cauline; cauline alternate or opposite, stipules 2, +- on stem. Inflorescence: cyme or pseudo-umbel or 1--2-flowered. Flower: bisexual [unisexual], radial or +- bilateral; sepals 5, free, overlapping in bud; petals generally 5, free, generally with nectar glands at base; stamens generally 5,10[15]; staminodes scale-like or 0; ovary generally 5-lobed, upper part elongating into beak in fruit, chambers 5, placentas axile, style 1, stigmas 5, free, persistent in fruit. Fruit: septicidal [loculicidal], mericarps 5, dry, generally 1-seeded, each persistent on 1 of 5 linear segments of beak that separate from central column by curving or coiling upward.
Genera In Family: 6 genera, 709 species: temperate, +- tropics. Some cultivated for ornament, perfume oils.
eFlora Treatment Author: Carlos Aedo, except as noted
Scientific Editor: Thomas J. Rosatti.
Genus: GeraniumView DescriptionDichotomous Key

Habit: Annual, perennial herb, often +- glandular, especially above. Stem: generally 1--4 mm wide in lower 1/2. Leaf: palmately lobed to divided, +- hairy; segments generally palmately lobed and/or toothed; upper alternate or opposite; blade generally round in outline, base generally cordate. Inflorescence: (1)2-flowered. Flower: radial (+- bilateral); sepals +- awned to mucronate; stamens 10, outer 5 opposite petals (lacking anthers in G. pusillum), inner 5 alternate petals, nectary glands 5, alternate petals. Fruit: mericarp generally ovoid, dehiscent, 1-seeded; basal callus generally present, often with long bristles.
Etymology: (Greek: crane, from fruit beak) Note: Geranium yeoi Aedo & Muñoz Garm., native to Atlantic island of Madeira, with petals (14.9)16.2--19.3(20.7) mm and stamen filaments (8.7)9.6--11.3(12.8) mm -- longer than in similar G. robertianum -- documented in NCo of Del Norte Co. (Zika 2009 Madroño 56:130).
eFlora Treatment Author: Carlos Aedo
Reference: [Aedo 2001 Anales Jard Bot Madrid 59:3--65; Aedo et al. 1998 Ann Missouri Bot Gard 85:594--630]
Unabridged Reference: [Aedo 2000--2001 Anales Jard Bot Madrid 58:39--82, 59:3--65; Aedo et al. 1998 Ann Missouri Bot Gard 85:594--630]
Geranium core-core Steud.
Habit: Perennial herb. Stem: ascending to erect, 1.5--7.5 dm; hairs sparse, stiff, reflexed, appressed. Leaf: blade 1.5--5.6 cm wide, divided 0.55--0.8 to base, segments 5--7, broadly wedge-shaped. Flower: pedicel 11--31 mm; sepals 3--5.5 mm, smooth, short-awned; petals 3.1--7.1 mm, rounded or +- notched, purple. Fruit: mericarp 2.6--3.2 mm, smooth, minutely strigose; beak 9.1--14.5 mm, narrow tip 0; stigmas 0.9--1.5 mm. Seed: faintly pitted.
Ecology: Disturbed sites; Elevation: < 200 m. Bioregional Distribution: NCo, NCoRO, n SNF, CCo, SnFrB, w SCo, WTR, c PR; Distribution Outside California: native to South America. Flowering Time: Mar--Oct Note: Previously misidentified as Geranium retrorsum DC., native to Australia.
Jepson eFlora Author: Carlos Aedo
Reference: [Aedo 2001 Anales Jard Bot Madrid 59:3--65; Aedo et al. 1998 Ann Missouri Bot Gard 85:594--630]
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Geranium core-core

botanical illustration including Geranium core-core

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Citation for this treatment: Carlos Aedo 2022, Geranium core-core, in Jepson Flora Project (eds.) Jepson eFlora, Revision 11,, accessed on April 20, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on April 20, 2024.

Geranium core-core
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©2012 Neal Kramer
Geranium core-core
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©2015 Vernon Smith
Geranium core-core
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©2013 Vernon Smith

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Geographic subdivisions for Geranium core-core:
NCo, NCoRO, n SNF, CCo, SnFrB, w SCo, WTR, c PR
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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).