Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora.



David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.


David J. Keil and Gregory K. Brown

Annual to subshrubs
Stems from taproot or ± branched caudex
Leaves simple, alternate, entire to pinnately dissected; teeth or lobes often ± bristle-tipped
Inflorescence: heads radiate or discoid, solitary or cymosely clustered; involucre bell-shaped, hemispheric, or obconic; phyllaries in 2–several series of unequal length, basal portion straw-colored to purplish, tips green; receptacle convex, naked or with short, triangular scales (not chaff)
Ray flowers 8–many; corollas yellow, white, pink, blue, or purple
Disk flowers 10–many; corollas yellow; style tips triangular to linear, acute
Fruit linear to club-shaped or obovoid, smooth or several–many-ribbed, glabrous to densely hairy; pappus of many unequal bristles (ray pappus sometimes 0)
Species in genus: ± 35 species: temp w North America
Etymology: (Greek: sword-like anthers)
Reference: [Hartman 1990 Phytologia 68:439–465]


M. canescens (Pursh) A. Gray


Annual to perennial herb < 12 dm, generally canescent-puberulent and often glandular
Stems 1–several from base, generally branched above and ± bushy
Leaves generally 3–10 cm, generally 2–6 mm wide, linear to obovate, subentire to dentate or minutely serrate; lower tapered; upper sometimes clasping
Inflorescence: heads radiate; phyllaries generally in 3–10 series, tips short-triangular to elongate, acuminate, spreading to bent backward, generally ± glandular or glabrous
Ray flowers many (0 in var. shastensis ); corollas blue-purple; ligules 1–2 cm
Disk flowers many; corollas 5.5–8 mm
Fruit 2.5–3.5 mm, narrowly obovate, weakly curved and ± flattened with 5–7 ribs on each face, glabrous or ± silky; pappus 6–8 mm
Ecology: Common. Many habitats
Elevation: 300–3400 m.
Bioregional distribution: Klamath Ranges, Cascade Range, Sierra Nevada, Transverse Ranges, Peninsular Ranges, Great Basin Floristic Province, Mojave Desert
Distribution outside California: w N.America
Variable; perhaps not a different sp. from M. asteroides.


var. shastensis (A. Gray) B.L. Turner

Annual to short-lived perennial herb
Stems 1–5 dm, spreading or erect; branches loosely spreading to ascending
Inflorescence: heads discoid or radiate; 6–12(14) mm, 10–15 mm wide (when pressed); involucres 6–9 mm
Ray flowers 0 or reduced, often sterile; style 0
Ecology: Various montane habitats
Elevation: 1500–3400 m.
Bioregional distribution: Klamath Ranges, Cascade Range, n Sierra Nevada, Modoc Plateau, White and Inyo Mountains
Distribution outside California: s Oregon, w Nevada
Flowering time: Jul–Sep
Synonyms: M. s. A. Gray, including var. eradiata (A. Gray) Cronquist & D.D. Keck
Horticultural information: DRN, SUN: 1, 2, 3, 6, 7, 15, 16.

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bioregional map for MACHAERANTHERA%20canescens%20var.%20shastensis being generated
YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps).

Retrieve Jepson Interchange Index to Plant Names entry for Machaeranthera canescens var. shastensis
Retrieve dichotomous key for Machaeranthera
Retrieve multiple-entry key (MEKA) for Machaeranthera
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
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