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Vascular Plants of California
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Arnica sororia
TWIN ARNICA


Higher Taxonomy
Family: Asteraceae (Compositae)View DescriptionDichotomous Key
Common Name: SUNFLOWER FAMILY
Habit: Annual to tree. Leaf: basal and/or cauline, alternate, opposite, rarely whorled, simple to 2+ × compound. Inflorescence: 1° inflorescence a head, resembling a flower, of several types (see below), 1--many in generally +- cyme-like cluster; each head generally with +- calyx-like involucre of 1--many series of phyllaries (involucre bracts); receptacle of head flat to conic or columnar, paleate (bearing paleae = receptacle bracts) or epaleate; flowers 1--many per head. Flower: bisexual, unisexual, or sterile, +- small, of several types (see below); calyx 0 or modified into +- persistent pappus of bristles, scales, and/or awns; corolla radial or bilateral (0), lobes generally (0)3--5; stamens 4--5, filaments generally free, generally fused to corolla at tube/throat junction, anthers generally fused into cylinder around style, anther base generally rounded or cordate (deeply sagittate or with tail-like appendages), tip (= flattened appendage) generally projecting beyond pollen sac; pistil 1, 2-carpeled, ovary inferior, 1-chambered, 1-seeded, placenta basal, style 1, tip generally +- 2-branched (except in some staminate disk flowers), branch tips truncate or generally bearing +- brush-like appendages; stigmas 2, generally on adaxial faces of style branches. Fruit: achene (also called a cypsela) (drupe in Chrysanthemoides), cylindric to ovoid, sometimes compressed, generally deciduous with pappus attached.
Genera In Family: +- 1500 genera, 23000 species: worldwide, many habitats. Note: Flower and head types differ in form and sexual condition. A disk flower has a generally radial corolla, with a cylindric tube, expanded throat, and generally 5 lobes. Disk flowers are generally bisexual and fertile but occasionally staminate with reduced ovaries. Discoid heads comprise only disk flowers. A radiant head is a variant of a discoid head, with peripheral disk flower corollas expanded, often bilateral. A ray flower corolla is bilateral, generally with a slender tube and flattened petal-like ray (single lip composed of generally 3 lobes). Ray flowers are generally pistillate or sterile (occasionally lacking styles). Radiate heads have peripheral ray flowers and central disk flowers. Disciform heads superficially resemble discoid heads, with pistillate or sterile flowers that lack rays, together with or separate from disk flowers. A ligulate flower is bisexual, with a bilateral, generally ephemeral corolla and 5-lobed ligule. Liguliflorous heads comprise only ligulate flowers. See glossary p. 31 for illustrations of family characteristics. Echinops sphaerocephalus L., Gaillardia aristata Pursh, Gaillardia pulchella Foug., Hymenothrix loomisii S.F. Blake, Tagetes erecta L., Thelesperma megapotamicum (Spreng.) Kuntze are waifs. Melampodium perfoliatum Kunth, historic urban waif. Ageratum conyzoides L., Guizotia abyssinica (L. f.) Cass., Santolina chamaecyparisus L., orth. var. are rare or uncommon escapes from cultivation. Dyssodia papposa, Ismelia carinata (Schousb.) Sch. Bip. [Chrysanthemum carinatum Schousb.], Mantisalca salmantica (L.) Briq. & Cavill. are historical or extirpated waifs in California. Inula helenium L. not documented in California. Taxa of Aster in TJM (1993) treated here in Almutaster, Doellingeria, Eurybia, Ionactis, Oreostemma, Sericocarpus, Symphyotrichum; Chamomilla in Matricaria; Bahia in Hymenothrix; Cnicus in Centaurea; Conyza in Erigeron and Laennecia; Dugaldia in Hymenoxys; Erechtites in Senecio; Hymenoclea in Ambrosia; Lembertia in Monolopia; Osteospermum ecklonis in Dimorphotheca; Picris echioides in Helminthotheca; Prionopsis in Grindelia; Raillardiopsis in Anisocarpus and Carlquistia; Schkuhria multiflora in Picradeniopsis; Trimorpha in Erigeron; Venidium in Arctotis; Viguiera in Aldama and Bahiopsis; Whitneya in Arnica. Amauriopsis in TJM2 (2012) treated here in Hymenothrix; Arida in Leucosyris; Bahia in Picradeniopsis; Eucephalus in Doellingeria.
Unabridged Note: Largest family of vascular plants in California and of eudicots globally.
eFlora Treatment Author: David J. Keil, except as noted
Scientific Editor: David J. Keil, Bruce G. Baldwin.
Genus: ArnicaView DescriptionDichotomous Key


Habit: Perennial herb, generally from long, naked rhizome. Leaf: basal 0 or generally withered by flowering, or present as sterile rosettes; cauline opposite. Inflorescence: heads radiate or discoid (radiant), 1--many in +- flat-topped clusters; generally erect in bud (nodding); involucre hemispheric to obconic; phyllaries generally in 2 +- equal series; receptacle +- flat, epaleate. Ray Flower: 0 or 5--22; ray yellow or yellow-orange. Disk Flower: many, generally bisexual; corolla generally soft-hairy, generally colored like rays; anther tip triangular; style branches flat, tips truncate, short-hair-tufted. Fruit: +- cylindric, 5--10-veined; pappus (0 or) of many barbed to +- plumose bristles, white to red-brown.
Etymology: (Latin or Greek: ancient name) Note: Diploid species sexual; polyploid species generally form seeds asexually.
eFlora Treatment Author: Steven J. Wolf & Theodore M. Barkley
Reference: Wolf 2006 FNANM 21:366--377
Arnica sororia Greene
NATIVE
Habit: Plant 1--5 dm from short, sparsely scaly rhizome, stalked-glandular, unevenly hairy distally; proximal axils glabrous or sparsely white-hairy. Stem: 1--several, branched or not. Leaf: basal densely clustered, cauline 3--6 pairs, crowded toward base, proximal petioled, blades 3.5--14.5 cm, +- oblanceolate, +- entire; distal leaves sessile, reduced. Inflorescence: heads radiate, 1--5; involucre 10--15 mm, widely hemispheric; phyllaries narrowly to +- widely lanceolate, hairy, stalked-glandular, ciliate, adaxial face glabrous. Ray Flower: 9--17; ray 10--30 mm, yellow-orange. Disk Flower: corolla stalked-glandular. Fruit: 3--5.5 mm, hairy, sometimes sparsely glandular; pappus short-barbed, white. Chromosomes: 2n=38.
Ecology: Uncommon. Open sagebrush scrub; Elevation: 1400--1800 m. Bioregional Distribution: GB; Distribution Outside California: to western Canada, Wyoming. Flowering Time: May--Jul Note: Similar to Arnica fulgens.
Jepson eFlora Author: Steven J. Wolf & Theodore M. Barkley
Reference: Wolf 2006 FNANM 21:366--377
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Arnica sororia

botanical illustration including Arnica sororia

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Citation for this treatment: Steven J. Wolf & Theodore M. Barkley 2012, Arnica sororia, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=1148, accessed on April 16, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 16, 2024.

No expert verified images found for Arnica sororia.



Geographic subdivisions for Arnica sororia:
GB
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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.
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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.
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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).