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Vascular Plants of California
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Isocoma acradenia var. acradenia

Higher Taxonomy
Family: Asteraceae (Compositae)View DescriptionDichotomous Key
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: IsocomaView DescriptionDichotomous Key

Habit: Subshrub; herbage glabrous, minutely scabrous, sessile- or stalked-glandular, long-soft-hairy, or tomentose. Stem: prostrate to erect, +- striate below, yellow-white or gray to red-brown, glabrous or variously hairy, often dotted with sessile resin glands. Leaf: alternate, sometimes clustered in axils, entire, toothed, or pinnately lobed, gland-dotted, sometimes gummy-resinous, light to dark gray-green. Inflorescence: heads discoid, in loose to tight cyme-like clusters, these borne at branch tips or in +- flat-topped or panicle-like 2° clusters; involucre obconic; phyllaries yellow-white proximally, cartilaginous, tips green; receptacle flat, epaleate. Flower: corolla yellow; tube narrowly cylindric, abruptly expanded into larger cylindric throat; lobes short, erect; style branch appendages triangular. Fruit: narrowly obconic, light tan, silky-hairy; hairs white, yellow, tan, or light red-tan; pappus of 1--2 series of white, +- yellow, or red-tan bristles +- 2 × fruit.
Etymology: (Greek: equal hair-tuft, from flowers) Note: Plants from southern San Diego Co. with pinnately lobed leaves resemble Isocoma tenuisecta Greene, not in California, but are more densely hairy.
eFlora Treatment Author: David J. Keil
Reference: [Nesom 2006 FNANM 20:439--445]
Unabridged Reference: Nesom 1991 Phytologia 70:69--114
Species: Isocoma acradeniaView Description 

Habit: Plant <= 1.3 m, rounded or open. Stem: erect or ascending, branched from ground or above, glabrous or minutely scabrous, yellow-white, shiny, becoming yellow-tan or gray with age. Leaf: 1.5--6 cm, 1.5--15 mm wide, linear, obovate or spoon-shaped, entire or toothed, gland-dotted, glabrous or minutely scabrous, generally light gray-green. Inflorescence: heads in loose to tight clusters of 4--5; involucre 4--5 mm, 4--5 mm diam; phyllaries 22--36 in 3--6 series, oblong, tips blunt, rounded, or acute, green or tan to 1/4 length of phyllary, swollen by glandular exudate below face, appearing wart-like. Flower: 12--27. Fruit: 2--3.5 mm; pappus 3--5.5 mm, white-yellow, bristles unequal.

Isocoma acradenia (Greene) Greene var. acradenia
Stem: <= 0.8 m. Leaf: <= 5 cm, not much-reduced above, entire. Inflorescence: involucre not closely subtended by bracts; phyllaries 22--28 in 3--4 series, tips rounded and not at all pointed, or occasionally weakly soft-pointed. Flower: 18--24. Chromosomes: 2n=24.
Ecology: Alkaline soils; Elevation: < 1100 m. Bioregional Distribution: SnJV, SCoR, SnBr, DMoj; Distribution Outside California: to Utah, Arizona, northwestern Mexico. Flowering Time: Aug--Nov
Jepson eFlora Author: David J. Keil
Reference: [Nesom 2006 FNANM 20:439--445]
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Isocoma acradenia var. acradeniabotanical illustration including Isocoma acradenia var. acradenia

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Citation for this treatment: David J. Keil 2012, Isocoma acradenia var. acradenia, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on July 15, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on July 15, 2024.

No expert verified images found for Isocoma acradenia var. acradenia.

Geographic subdivisions for Isocoma acradenia var. acradenia:
SnJV, SCoR, SnBr, DMoj
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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 occurrence).


Data provided by the participants of the  Consortium of California Herbaria.

View all CCH records
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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 Flowering-Fruiting Monthly Counts

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).