The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Sonora croton, Sonoran croton

trans-Pecos croton

Habit Shrubs, 8–16 dm, monoecious. Shrubs, 1–4 dm, dioecious.
Stems

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

much branched proximally, coarsely stellate-tomentose.

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 each 1 glandular papilla, 0.1 mm;

petiole 0.1–0.4(–0.6) cm, 1/10–1/5 blade length, glands absent at apex;

blade ovate to elliptic-ovate, 1–3(–4.5) × 0.5–1.5(–2) cm, base usually rounded to obtuse, rarely acute, margins entire, apex acute or rounded, abaxial surface pale green to pale yellow, stellate-tomentose, adaxial surface darker green, stellate-tomentose.

Inflorescences

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

unisexual;

staminate racemes, 1–3.3 cm, flowers 1–8;

pistillate congested racemes, 0.1–0.3 cm, flowers 1–3.

Pedicels

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

staminate 1 mm, pistillate 0–0.5 mm.

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 (4–)5, 2 mm, abaxial surface stellate-hairy;

petals (4–)5, narrowly oblanceolate, 1.8–2 mm, abaxial surface nearly glabrous;

stamens 9–12.

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, 1 mm, margins entire, apex straight to slightly incurved, abaxial surface stellate-hairy;

petals 0 or rudimentary;

ovary 3-locular;

styles 3, 1.5–2 mm, 2-fid to base, terminal segments 6.

Capsules

7–8 × 5–6 mm, smooth;

columella apex with 3 rounded, inflated lobes.

4–5 × 5.5–6 mm, smooth;

columella apex with 3 rounded, inflated lobes.

Seeds

6–7 × 3–4 mm, shiny.

3.6–4.7 × 2.8–3.4 mm, shiny.

Croton sonorae

Croton sancti-lazari

Phenology Flowering Jul–Sep. Flowering Oct–Nov.
Habitat Rocky slopes, desert scrub. Rocky hillsides.
Elevation 500–1100 m. (1600–3600 ft.) 900–1200 m. (3000–3900 ft.)
Distribution
from FNA
AZ; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
TX; Mexico (Chihuahua, Coahuila)
[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 sancti-lazari in the flora area grows only in Brewster and Presidio counties.

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

Source FNA vol. 12, p. 223. FNA vol. 12, p. 222.
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. setigerus, C. soliman, C. sonorae, C. suaveolens, C. texensis, C. wigginsii
Synonyms C. attenuatus, C. pringlei C. abruptus
Name authority Torrey: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 194. (1859) Croizat: J. Arnold Arbor. 26: 185. (1945)
Web links