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Key to families | Table of families and genera

Previous taxon Indexes to all accepted names and synonyms:
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Joshua R. McDill

Annual, perennial herb [shrub, tree, vine]. Stem: generally erect [climbing], branched, glabrous to hairy. Leaf: cauline, alternate to opposite or whorled, simple, generally sessile, linear to obovate, entire to minutely toothed or ciliate, teeth occasionally gland-tipped; stipules small, dark-colored, spheric glands, or 0. Inflorescence: raceme, panicle, or cyme [spike]. Flower: bisexual, radial; sepals [4]5, free; petals = sepals in number, free to adherent; stamens 5[4 or 10], alternate petals, filaments fused basally into a cup-like structure surrounding ovary base; staminodes present, alt stamens at cup rim, or 0; ovary superior, carpels 2–5, fused, styles 2–5, = carpel number, free or partly fused. Fruit: capsule, generally dehiscent [drupe in some tropical species], generally 10-seeded.
13 genera, ± 250 species: cosmopolitan, most temperate, some cultivated. [McDill et al. 2009 Syst Bot 34:386–405] Hesperolinon, Sclerolinon are evolutionary lineages within Linum. —Scientific Editors: Douglas H. Goldman, Robert Patterson, Bruce G. Baldwin.
Unabridged references: [Robertson 1971 J Arnold Arbor 52:649–665]

Key to Linaceae

Annual, erect, 3–50 cm, generally branched (at least in inflorescence). Leaf: generally alternate (occasionally opposite or whorled), generally sessile, 4–35 mm, 1–3(6) mm wide, thread-like or linear to ovate or obovate, margin gland-toothed or entire; stipular glands present or 0. Inflorescence: generally open or dense cyme, bracted; pedicel thread-like, generally ascending to erect. Flower: sepals lanceolate to ovate, acute or acuminate, glabrous or hairy, or margins glandular-ciliate; petals free, 1–12 mm, yellow, white, or pink, generally with small appendages near base; staminodes 0; carpels 2–3, stigmas linear (± = style in width). Fruit: smooth. Seed: ± triangular in ×-section, acute.
12–13 species: especially California, often on serpentine. (Greek, Latin: western flax) [Sharsmith 1961 Univ Calif Publ Bot 32:235–314] Hesperolinon serpentinum, used in TJM (1993), is not validly published.

Key to Hesperolinon

H. clevelandii (Greene) Small
Plant 5–20 cm, ± glabrous. Leaf: alternate, linear. Inflorescence: unequally forked (main axis obvious); pedicels 5–25 mm. Flower: sepals 1.5–2.5 mm; petals 0.5–1.5 mm, yellow; stamens 1.5–3 mm, anthers yellow; ovary chambers 6, styles 3, generally 0.5–1 mm, yellow.
n=18. Chaparral margins, oak woodland, often on serpentine; 150–1400 m. Outer North Coast Ranges, c&s Inner North Coast Ranges, s High North Coast Ranges, e San Francisco Bay Area. [Linum clevelandii Greene] Like Hesperolinon micranthum except flower color. May–Jul [Online Interchange]

Previous taxon: Hesperolinon californicum
Next taxon: Hesperolinon congestum


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Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora,, accessed on Nov 27 2015
Citation for this treatment: [Author of taxon treatment] 2013. Hesperolinon, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on Nov 27 2015

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Geographic subdivisions indicated for the distribution of Hesperolinon clevelandii Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
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.
Blue line denotes eFlora flowering time.