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Sonora croton, Sonoran croton

Wiggins' croton

Habit Shrubs, 8–16 dm, monoecious. Shrubs, 2–10 dm, dioecious.
Stems

much-branched distally, canescent when young, becoming glabrate.

densely branched, appressed-lepidote.

Leaves

sometimes clustered near inflorescences;

stipules subulate, to 1 mm;

petiole 0.4–1 cm, 1/4–1/2 leaf blade length, glands absent at apex;

blade ovate to broadly lanceolate, 0.8–4 × 0.6–2 cm, base cuneate to rounded or cordate, margins entire, not undulate, ciliate-glandular, apex acute to acuminate, abaxial surface pale green, sparsely whitish stellate-hairy, adaxial surface darker green, glabrate.

not clustered;

stipules absent;

petiole 1–4 cm, usually less than 1/2 blade length, glands absent at apex;

blade narrowly elliptic to linear-oblong, 2–8.5 × 0.6–1.5 cm, more than 2 times as long as wide, base obtuse, margins entire, apex obtuse to rounded, abaxial surface pale green, adaxial surface darker green, both densely pale stellate-lepidote.

Inflorescences

bisexual or staminate, racemes, 2–14 cm, staminate flowers 10–25, pistillate flowers 3–5(–8).

unisexual, racemes or thyrses;

staminate 1–3.5(–10) cm, flowers 3–8(–15);

pistillate 0.5–1 cm, flowers 1–6.

Pedicels

staminate 1–1.5 mm, pistillate 1–4 mm.

staminate 1–7 mm, pistillate 1–2 mm (4–7 mm in fruit).

Staminate flowers

sepals 5, 1–1.5 mm, abaxial surface sparsely stellate-hairy;

petals 5, lanceolate, 1.5–2 mm, abaxial surface glabrous except margins villous;

stamens 13–16.

sepals 5, 1 mm, abaxial surface stellate-hairy;

petals 0;

stamens 10–15.

Pistillate flowers

sepals 5, equal, 1.5–2 mm, margins entire, apex incurved, abaxial surface sparsely stellate-hairy;

petals papillae, 0.5 mm;

ovary 3-locular;

styles 3, 2–3 mm, 2-fid, terminal segments 6.

sepals 5, equal, 2 mm, margins entire, apex incurved, abaxial surface stellate-lepidote;

petals 0;

ovary 3-locular;

styles 3, 1.5–2.5 mm, 2–3 times 2-fid, terminal segments 12–24.

Capsules

7–8 × 5–6 mm, smooth;

columella apex with 3 rounded, inflated lobes.

7–10 × 6–8 mm, smooth;

columella 3-winged.

Seeds

6–7 × 3–4 mm, shiny.

6.5–7 × 2–3 mm, dull.

2n

= 28.

Croton sonorae

Croton wigginsii

Phenology Flowering Jul–Sep. Flowering Feb–May.
Habitat Rocky slopes, desert scrub. Sand dunes.
Elevation 500–1100 m. (1600–3600 ft.) 10–100 m. (0–300 ft.)
Distribution
from FNA
AZ; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Croton sonorae is widely distributed in Mexico and extends into southern Arizona in Maricopa, Pima, and Pinal counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Croton wigginsii is closely related to C. californicus but more robust in its habit and floral features, and is restricted to sand dunes in a limited area of the Sonoran Desert. In the flora area, C. wigginsii is known only from Yuma County, Arizona, and Imperial County, California.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 223. FNA vol. 12, p. 224.
Parent taxa Euphorbiaceae > Croton Euphorbiaceae > Croton
Sibling taxa
C. alabamensis, C. argenteus, C. argyranthemus, C. californicus, C. capitatus, C. ciliatoglandulifer, C. cortesianus, C. coryi, C. dioicus, C. elliottii, C. fruticulosus, C. glandulosus, C. heptalon, C. humilis, C. incanus, C. leucophyllus, C. lindheimeri, C. lindheimerianus, C. linearis, C. michauxii, C. monanthogynus, C. parksii, C. pottsii, C. punctatus, C. sancti-lazari, C. setigerus, C. soliman, C. suaveolens, C. texensis, C. wigginsii
C. alabamensis, C. argenteus, C. argyranthemus, C. californicus, C. capitatus, C. ciliatoglandulifer, C. cortesianus, C. coryi, C. dioicus, C. elliottii, C. fruticulosus, C. glandulosus, C. heptalon, C. humilis, C. incanus, C. leucophyllus, C. lindheimeri, C. lindheimerianus, C. linearis, C. michauxii, C. monanthogynus, C. parksii, C. pottsii, C. punctatus, C. sancti-lazari, C. setigerus, C. soliman, C. sonorae, C. suaveolens, C. texensis
Synonyms C. attenuatus, C. pringlei C. arenicola
Name authority Torrey: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 194. (1859) L. C. Wheeler: Contr. Gray Herb. 124: 37. (1939)
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