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Key to families | Table of families and genera
Indexes to all accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
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 (involucral 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.
± 1500 genera, 23000 species: worldwide, many habitats. 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; 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 Bahia; Trimorpha in Erigeron; Venidium in Arctotis; Whitneya in Arnica. Taxa of Arida in TJM2 treated here in Leucosyris. —Scientific Editors: David J. Keil, Bruce G. Baldwin.
Unabridged note: Largest family of vascular plants in California and of eudicots globally.
Key to Asteraceae
Annual 0.5–10(20 cm), ± green to gray, woolly to cobwebby. Stem: 0, or 1, erect, or 2–10, ± decumbent to ascending, generally unbranched or branched proximally, equally or more leafy distally. Leaf: alternate, sessile or petioled, oblanceolate to spoon-shaped, entire, base ± yellow, ± hard; distal leaves subtending heads, ± crowded, largest >= proximal leaves. Inflorescence: heads disciform, sessile, single or 2–40+ per group; involucre 0, simulated by paleae or leaves; receptacle length 0.8–1.3 or 4–6 × width, ± conic, acuminate, bristly; paleae of pistillate flowers open, lanceolate to obovate, acute, flat to concave or ± folded, persistent, ± glabrous, obscurely parallel-veined, veins 5+, margin ± continuous, thinned but scarcely winged; paleae of disk flowers generally 5, ± enlarged, erect proximally, erect to spreading distally, open, obovate, obtuse, cartilaginous, proximally ± yellow, distally green and tomentose adaxially. Pistillate flower: (3)5–25, all subtended by paleae; corolla obscure, narrowly cylindric. Disk flower: staminate, 2–6(12); pappus 0; corolla (3)4(5)-lobed, ± bilateral; anther base tailed, tip ± triangular; style tips ± linear-oblong; pappus 0. Fruit: falling free of paleae, ± obovoid, compressed front-to-back, smooth, dull to ± shiny, corolla scar terminal; pappus 0.Key to Hesperevax
3 species: western California, southern Oregon. (Greek: western Evax) [Morefield 2006 FNANM 19:467–470] Apparent sister of Ancistrocarphus; bristly receptacle unique. Historical California specimens of Diaperia [Evax sect. Diaperia], native central Arizona and eastward, are likely label errors.
Unabridged references: [Morefield 1992 Syst Bot 17:293–310]
Previous taxon: Hemizonia congesta subsp. tracyi
Next taxon: Hesperevax acaulis
Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on Apr 17 2014
Citation for this treatment: [Author of taxon treatment] 2012. Hesperevax, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=10399, accessed on Apr 17 2014
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