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Pentachaeta alsinoides

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: PentachaetaView DescriptionDichotomous Key

Habit: Annual from slender taproot, +- hairy (but appearing glabrous). Stem: generally simple or branching proximally, erect, generally flexible, glabrous to hairy, green to +- red. Leaf: generally narrowly linear, ciliate, green. Inflorescence: heads radiate, disciform, or discoid, nodding in bud, 1 or in open, +- flat-topped cluster; peduncle slender; involucre 3--7 mm, generally bell-shaped; phyllaries in 2--3(4) series, graduated or +- equal, lanceolate to (ob)ovate, green, margins widely scarious; receptacle flat to slightly convex, epaleate. Ray Flower: present or 0, or corolla reduced to tube; corolla white, yellow, 2-colored yellow and white, or +- red. Disk Flower: 4--90+; corolla yellow to +- red or maroon; style tips linear, acute. Fruit: 1.5--3 mm, oblong-fusiform, generally compressed, generally hairy; pappus of 0--20 fragile, slender bristles.
Species In Genus: 6 species: California, northwestern Baja California. Etymology: (Greek: five bristles, from pappus) Note: Similar, closely related to Rigiopappus, Tracyina.
eFlora Treatment Author: David J. Keil & Meredith A. Lane
Reference: Keil 2007 Madroño 54:343--344; Nesom 2006 FNANM 20:46--48
Unabridged Reference: Van Horn 1973 Univ Calif Publ Bot 65:1--41

Pentachaeta alsinoides Greene
Stem: 3--14 cm, hairy below heads. Leaf: < 3.5 cm, 1 mm wide; adaxially hairy; abaxially generally glabrous. Inflorescence: heads <= 200 per pl; peduncle hairy; involucre narrowly obconic; phyllaries elliptic, glabrous or sparsely hairy. Ray Flower: generally 5; ray 0 or < 1 mm, corolla generally reduced to tube, light yellow, tips +- red. Disk Flower: generally 4; corolla 3-lobed, colored as ray flowers. Fruit: pappus bristles 3, slightly expanded at base. Chromosomes: 2n=18.
Ecology: Grassy areas, open woodland, chaparral openings; Elevation: < 550 m. Bioregional Distribution: NCoR, SNF, n CCo (San Francisco), SnFrB, SCoR, w WTR. Flowering Time: Mar--Jun
Synonyms: Chaetopappa alsinoides (Greene) D.D. Keck;
Jepson eFlora Author: David J. Keil & Meredith A. Lane
Reference: Keil 2007 Madroño 54:343--344; Nesom 2006 FNANM 20:46--48
Unabridged Reference: Van Horn 1973 Univ Calif Publ Bot 65:1--41
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botanical illustration including Pentachaeta alsinoides


Citation for this treatment: David J. Keil & Meredith A. Lane 2012, Pentachaeta alsinoides, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on November 15, 2018.

Citation for the whole project: Jepson Flora Project (eds.) 2018, Jepson eFlora,, accessed on November 15, 2018.

Geographic subdivisions for Pentachaeta alsinoides:
NCoR, SNF, n CCo (San Francisco), SnFrB, SCoR, w WTR.
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.