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Vascular Plants of California
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Centromadia parryi subsp. rudis

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; 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: CentromadiaView DescriptionDichotomous Key

Common Name: SPIKEWEED
Habit: Annual [perennial herb] 1--12 dm. Stem: prostrate to +- erect. Leaf: simple, basal and cauline, opposite proximally, often withered before flower, most alternate, +- sessile, oblanceolate to linear or lance-linear, proximal generally 1--2 pinnately lobed, lobes toothed or entire, sometimes bristly-ciliate, distal entire, generally spine-tipped, faces glabrous or scabrous and/or coarse- to soft-hairy or puberulent, often also glandular. Inflorescence: heads radiate, congested or in spike- to panicle- or umbel-like clusters; peduncle bracts generally spine-tipped; involucre +- obconic or urn-shaped, 3--8+ mm diam; phyllaries 5--75+, lanceolate or oblanceolate, each +- 1/2-enclosing ray ovary, falling with fruit or both persistent and head or flower branch dispersing as unit, scabrous and/or coarse- to soft-hairy or puberulent, often also glandular; receptacle flat to convex, minutely bristly; paleae subtending all or most disk flowers, free. Ray Flower: 5--75+; corolla yellow, ray 2--6 mm. Disk Flower: 6--200+, generally staminate; corolla 2--5 mm, yellow, tube < throat, tube/throat glabrous, lobes deltate, abaxially often minutely bristly; anthers +- red to dark purple or yellow to +- brown, tips ovate; style glabrous proximal to branches, tips ovate to awl-shaped, densely bristly.; anther bases acute to sagittate. Fruit: ray fruit 2--3 mm, +- compressed, bulging abaxially, glabrous, beaked or elevated adaxially; pappus 0; disk pappus 0 or of 3--12 linear, awl-shaped or oblanceolate scales.
Species In Genus: 4 species: California, southern Oregon, northern Baja California (alien elsewhere in western United States, New York). Etymology: (Latin: prickly Madia) Note: Self-sterile.
eFlora Treatment Author: Bruce G. Baldwin
Reference: Baldwin & Strother 2006 FNANM 21:276--279
Unabridged Reference: Carlquist et al. 2003 Tarweeds and silverswords: evolution of the Madiinae; Venkatesh 1958 Evolution 39:1236--1241
Species: Centromadia parryiView Description 

Habit: Plant 1--7 dm. Leaf: glabrous, scabrous-puberulent, or +- coarse-hairy to soft-hairy, glandular or not, glands yellow. Inflorescence: involucre 2.5--10 mm. Disk Flower: anthers yellow, +- brown, or +- red to dark purple. Fruit: disk pappus of 3--5, linear or awl-shaped scales.

Centromadia parryi subsp. rudis (Greene) B.G. Baldwin
Leaf: scabrous-puberulent and generally +- coarsely hairy or bristly-ciliate, not glandular or with scattered, minute, sessile or stalked, +- yellow glands. Inflorescence: peduncle bracts scabrous-puberulent and generally +- coarse-hairy or bristly-ciliate, not glandular or with scattered, minute, sessile or stalked, +- yellow glands; involucre 3.5--5 mm; paleae lacking purple lines. Ray Flower: ray 2--3 mm. Disk Flower: anthers yellow or +- brown. Chromosomes: 2n=22.
Ecology: Grassland, edges of marshes and vernal pools, disturbed sites; Elevation: < 500 m. Bioregional Distribution: s NCoRI (rare), n&c GV, MP (Ash Creek vicinity, alien?). Flowering Time: Jun--Oct
Synonyms: Hemizonia parryi subsp. rudis (Greene) D.D. Keck
Jepson eFlora Author: Bruce G. Baldwin
Reference: Baldwin & Strother 2006 FNANM 21:276--279
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
Listed on CNPS Rare Plant Inventory

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Botanical illustration including Centromadia parryi subsp. rudis

botanical illustration including Centromadia parryi subsp. rudis


Citation for this treatment: Bruce G. Baldwin 2012, Centromadia parryi subsp. rudis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on April 19, 2021.

Citation for the whole project: Jepson Flora Project (eds.) 2021, Jepson eFlora,, accessed on April 19, 2021.

Centromadia parryi subsp. rudis
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© 2003 George W. Hartwell
Centromadia parryi subsp. rudis
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© 2013 Neal Kramer
Centromadia parryi subsp. rudis
click for enlargement
© 2013 Neal Kramer
Centromadia parryi subsp. rudis
click for enlargement
© 2013 Neal Kramer
Centromadia parryi subsp. rudis
click for enlargement
© 2015 Chris Winchell
Centromadia parryi subsp. rudis
click for enlargement
© 2013 Neal Kramer

More photos of Centromadia parryi subsp. rudis in CalPhotos

Geographic subdivisions for Centromadia parryi subsp. rudis:
s NCoRI (rare), n&c GV, MP (Ash Creek vicinity, alien?).
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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).


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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).