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Hemizonia congesta

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, Eucephalus, 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; Whitneya in Arnica. Amauriopsis in TJM2 (2012) treated here in Hymenothrix; Arida in Leucosyris; Bahia in Picradeniopsis.
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: HemizoniaView Description 


Species In Genus: 1 sp. Etymology: (Greek: 1/2 belt or girdle, fruit 1/2 enfolded by phyllary) Note: Other taxa in TJM (1993) moved to Centromadia (spiny-leaved taxa), Deinandra.
eFlora Treatment Author: Bruce G. Baldwin
Reference: Baldwin & Strother 2006 FNANM 21:291--293
Unabridged Reference: Babcock & Hall 1924 Univ Calif Publ Bot 13:15--100; Carlquist 2003 Tarweeds and silverswords: evolution of the Madiinae (Asteraceae)

Hemizonia congesta DC.
Habit: Annual 5--80 cm, often aromatic. Stem: +- erect. Leaf: basal and cauline, proximal opposite or in rosette, sometimes persistent, most alternate, sessile, 5--18+ cm, 2--8(12) mm wide, narrowly elliptic to linear or lance-linear, minutely serrate or entire, generally puberulent or coarse- to silky-hairy, distal often also stalked-glandular. Inflorescence: heads radiate, 1 or in +- panicle-, raceme-, or spike-like clusters or in tight groups; involucre hemispheric to +- urn-shaped or spheric, 3--8+ mm diam (rarely subtended by calyx-like set of 5--7 bractlets); phyllaries 5--14 in 1 series, linear to lanceolate or oblanceolate, each generally 1/2 enveloping a subtended ray ovary, falling with fruit, 3.5--12 mm, coarse- or soft-hairy, stalked-glandular; receptacle flat to conic, glabrous; paleae fused, forming cells around each disk flower, scarious, +- liquifying. Ray Flower: 5--14; corolla white or yellow, ray 5--12 mm, often purple-veined abaxially. Disk Flower: 5--60+, staminate; corolla 2.5--3.5 mm, white or yellow, tube < throat, lobes deltate; anthers +- dark purple, tips widely ovate to ovate-deltate; style glabrous proximal to branches, tips lanceolate to awl-shaped, densely hairy.; anther bases cordate-sagittate to sagittate. Fruit: ray fruit 2--3.5 mm, nearly round in ×-section (except +- flattened adaxially) or +- 3- angled (abaxially generally +- widely 2-faced, adaxially +- flattened to slightly bulging), glabrous, black, tip sometimes beaked, beak inconspicuous, straight, diam > length, pappus 0; disk fruit 0, pappus 0. Chromosomes: 2n=28.
Note: Self-sterile.
Jepson eFlora Author: Bruce G. Baldwin
Reference: Baldwin & Strother 2006 FNANM 21:291--293
Unabridged Reference: Babcock & Hall 1924 Univ Calif Publ Bot 13:15--100; Carlquist 2003 Tarweeds and silverswords: evolution of the Madiinae (Asteraceae)
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Key to Hemizonia congesta

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Citation for this treatment: Bruce G. Baldwin 2012, Hemizonia congesta, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on November 13, 2018.

Citation for the whole project: Jepson Flora Project (eds.) 2018, Jepson eFlora,, accessed on November 13, 2018.

Hemizonia congesta subsp. luzulifolia
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© 2016 Neal Kramer
Hemizonia congesta subsp. lutescens
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© 1994 John Game
Hemizonia congesta subsp. luzulifolia
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© 2007 Neal Kramer
Hemizonia congesta subsp. luzulifolia
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© 2016 Steve Matson
Hemizonia congesta subsp. clevelandii
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© 2016 Keir Morse
Hemizonia congesta subsp. luzulifolia
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© 2003 George W. Hartwell

More photos of Hemizonia congesta in CalPhotos

Geographic subdivisions for Hemizonia congesta:
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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).

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