1. Branchlets rigid, thorn-tipped; shrubs evergreen. | → 2 |
2. Leaf blades pinnately veined, adaxial surfaces green, shiny, abaxial surfaces pale green. | C. spinosus |
2. Leaf blades 3-veined from base (lateral basal veins sometimes obscure in C. fendleri), adaxial surfaces pale green to dark green or grayish green, dull, abaxial surfaces pale to grayish green. | → 3 |
3. Leaf blades 20–60 × 10–30 mm, abaxial surfaces pale green, appressed-puberulent, glabrescent, adaxial surfaces grayish green, glabrate. | C. incanus |
3. Leaf blades 5–30 × 3–18 mm, abaxial surfaces pale green to grayish green, glabrous, sparsely puberulent, or appressed-villosulous to tomentulose, especially along veins, adaxial surfaces dark to pale green or grayish green, glabrous, glabrate, or appressed-villosulous. | → 4 |
4. Shrubs 1.5–4 m, stems erect; inflorescences usually paniclelike, sometimes racemelike, (3–)5–15 cm. | C. leucodermis |
4. Shrubs 0.5–1.5 m, stems erect, ascending, or spreading; inflorescences umbel-like or racemelike, 1–3.5(–4) cm. | → 5 |
5. Stems ascending to spreading, not rooting at nodes; leaf blade adaxial surfaces pale to grayish green, glabrate. | C. cordulatus |
5. Stems erect, ascending, or spreading, rooting at proximal nodes; leaf blade adaxial surfaces dark green, appressed villosulous or glabrous. | C. fendleri |
1. Branchlets flexible to rigid, not thorn-tipped (sometimes weakly thorn-tipped in C. oliganthus); shrubs deciduous, semideciduous, or evergreen. | → 6 |
6. Leaf blades pinnately veined (proximal pair of secondary veins rarely more prominent and longer than distal pairs). | → 7 |
7. Leaf blade margins usually entire, rarely denticulate distally, adaxial surfaces glabrous or weakly puberulent. | → 8 |
8. Shrubs 0.3–0.8 m; inflorescences usually umbel-like, sometimes racemelike. | → 9 |
9. Sepals, petals, and nectaries white; petioles 0.5–1 mm. | C. microphyllus |
9. Sepals, petals, and nectaries blue; petioles 1–3 mm. | C. foliosus |
8. Shrubs 1–3 m; inflorescences racemelike to paniclelike. | → 10 |
10. Shrubs deciduous; leaf blades flat. | → 11 |
11. Leaf blades 6–25 mm, adaxial surfaces ± shiny; capsules usually not lobed, sometimes weakly lobed. | C. parvifolius |
11. Leaf blades 20–80 mm, adaxial surfaces dull; capsules lobed. | C. integerrimus |
10. Shrubs evergreen or semideciduous; leaf blades ± cupped. | → 12 |
12. Sepals and petals usually white, rarely pale blue; capsules lobed, valves viscid, crested; leaf blade adaxial surfaces dull to ± shiny. | C. palmeri |
12. Sepals and petals pale blue to blue; capsules not lobed, valves not conspicuously viscid, not or weakly crested; leaf blade adaxial surfaces shiny. | C. spinosus |
7. Leaf blade margins serrulate to denticulate (sometimes entire in C. hearstiorum), adaxial surfaces puberulent, pilosulous, villosulous, strigillose, or glandular-papillate, (sometimes glabrous in C. foliosus). | → 13 |
13. Leaf blade margins not revolute. | → 14 |
14. Shrubs 0.2–0.3(–0.5) m; stems spreading; capsules 4–5 mm wide; leaf blade surfaces pilosulous. | C. diversifolius |
14. Shrubs 1–3.5 m; stems erect to ascending; capsules 3–4 mm wide; leaf blade surfaces villosulous to strigillose or glabrate. | → 15 |
15. Branchlets green; petiole 1–3 mm; leaf blade margins usually wavy, sometimes not. | C. foliosus |
15. Branchlets pale green to grayish green and glaucous; petiole 2–8 mm; leaf blade margins not wavy. | C. lemmonii |
13. Leaf blade margins revolute. | → 16 |
16. Branchlets lanate to woolly, glabrescent; leaf blade abaxial surfaces cobwebby, soon glabrescent; inflorescences paniclelike, 5–15 cm. | C. parryi |
16. Branchlets puberulent to tomentulose; leaf blade abaxial surfaces variously hairy, but neither cobwebby nor glabrescent; inflorescences umbel- or racemelike, 1–5(–8) cm. | → 17 |
17. Leaf blade adaxial surfaces strigillose or sparsely puberulent, not glandular papillate. | → 18 |
18. Leaf blades oblong, elliptic, or suborbiculate, 6–25 × 4–15 mm, adaxial surfaces sparsely puberulent, veins furrowed. | C. impressus |
18. Leaf blades narrowly elliptic, narrowly oblong, or linear, 5–16 × 2–8 mm, adaxial surfaces strigillose, veins not furrowed. | C. dentatus |
17. Leaf blade adaxial surfaces glandular-papillate, sometimes also puberulent or villosulous. | → 19 |
19. Shrubs 1–5 m; stems erect to ascending; leaf blades 12–50 × 6–15 mm; capsules 2–3 mm wide. | C. papillosus |
19. Shrubs 0.1–0.3 m; stems prostrate to spreading, some flowering branches ascending; leaf blades 8–20 × 2–10 mm; capsules 4–5 mm wide. | C. hearstiorum |
6. Leaf blades 3-veined from base (proximal pair of secondary veins longer than those above, sometimes equaling central vein). | → 20 |
20. Leaf blade margins usually entire, rarely denticulate or serrulate distally. | → 21 |
21. Petioles 0.5–1 mm; leaves often fascicled, blades 2–10 × 1–6 mm; se United States. | C. microphyllus |
21. Petioles (1–)1.5–12 mm; leaves not fascicled, blades 6–80 × 3–45 mm; w United States. | → 22 |
22. Branchlets light gray; capsules prominently rugose. | C. incanus |
22. Branchlets pale green or green to grayish green or brown; capsules smooth to ± rugulose. | → 23 |
23. Shrubs 0.5–1 m; leaf blades widely elliptic to suborbiculate; inflorescences umbel-like to racemelike, 1.5–4 cm; sepals and petals white; nectary yellow to yellow-green. | C. martini |
23. Shrubs 1–4 m; leaf blades elliptic, oblong-elliptic, lanceolate, or ovate; inflorescences racemelike to paniclelike, 3–25 cm; sepals and petals white or blue; nectary usually white or blue, rarely pink. | → 24 |
24. Leaf blades 6–25 mm, adaxial surfaces ± shiny; capsules usually not lobed, sometimes weakly lobed. | C. parvifolius |
24. Leaf blades (10–)20–80 mm, adaxial surfaces dull; capsules lobed. | C. integerrimus |
20. Leaf blade margins serrate, serrulate, or denticulate (rarely entire in C. cyaneus). | → 25 |
25. Leaf blades (20–)25–100(–130) × 10–64 mm, margins serrate to serrulate, teeth (35–)40–150+; sepals and petals white to cream (sometimes pink-tinged in C. sanguineus, blue in C. arboreus). | → 26 |
26. Leaf blades leathery, resinous, aromatic, adaxial surfaces shiny. | C. velutinus |
26. Leaf blades herbaceous, not resinous, not aromatic, adaxial surfaces dull. | → 27 |
27. Leaf blades usually elliptic to lanceolate, sometimes ovate or oblanceolate; inflorescences terminal, globose to hemispheric. | C. herbaceus |
27. Leaf blades ovate, oblong-ovate, or widely elliptic; inflorescences terminal or axillary, cylindric to conic. | → 28 |
28. Shrubs evergreen; branchlets brown, tomentulose; sepals, petals, and nectaries blue; California Channel Islands. | C. arboreus |
28. Shrubs deciduous; branchlets green to reddish brown, puberulent, glabrescent; sepals, petals, and nectaries usually white to cream, sometimes pink-tinged; mainland United States. | → 29 |
29. Leaf blade apices usually acuminate to acute, rarely obtuse; capsules not lobed, valves ± rugulose, crested; e North America. | C. americanus |
29. Leaf blade apices acute to rounded; capsules weakly lobed near apex, valves smooth, not or sometimes weakly crested; w North America (disjunct in Michigan). | C. sanguineus |
25. Leaf blades 5–50 × 3–30 mm, margins usually denticulate, sometimes serrulate (rarely entire in C. cyaneus), teeth 19–71; sepals and petals blue (white in C. martini, rarely white in C. oliganthus and C. thyrsiflorus). | → 30 |
30. Leaf blade margins revolute. | → 31 |
31. Branchlets usually round, sometimes ± angled, in cross section, lanate to woolly, glabrescent; leaf blade abaxial surfaces cobwebby, soon glabrescent. | C. parryi |
31. Branchlets angled in cross section, sparsely puberulent or glabrous; leaf blade abaxial surfaces puberulent to villosulous. | C. griseus |
30. Leaf margins not revolute (sometimes incompletely revolute in C. thyrsiflorus). | → 32 |
32. Branchlets angled in cross section. | → 33 |
33. Branchlets often tuberculate (tubercles minute, brownish); inflorescences 15–30(–40) cm, paniclelike; capsules deeply lobed. | C. cyaneus |
33. Branchlets not tuberculate; inflorescences 2.5–9 cm, usually racemelike, rarely paniclelike; capsules weakly lobed. | C. thyrsiflorus |
32. Branchlets round in cross section (rarely angled in cross section in C. oliganthus). | → 34 |
34. Sepals and petals white, nectaries pale yellow to yellow-green; leaf blade margins serrulate distal to middle. | C. martini |
34. Sepals and petals pale blue to blue, nectaries usually pale to dark blue or purplish blue, rarely white; leaf blade margins denticulate or serrulate most of length. | → 35 |
35. Branchlets reddish brown to brown; leaf blades ovate to widely elliptic. | → 36 |
36. Leaf blade abaxial surfaces glabrate to hirtellous; petiole 3–8 mm; capsules 4–7 mm wide. | C. oliganthus |
36. Leaf blade abaxial surfaces tomentose to tomentulose; petiole 1–4 mm; capsules 3–4 mm wide. | C. tomentosus |
35. Branchlets green, pale green, or grayish green; leaf blades narrowly elliptic, oblong-elliptic, or oblanceolate. | → 37 |
37. Branchlets green; leaf blades ± folded lengthwise, margins usually ± wavy, sometimes not; capsule valves not or weakly crested. | C. foliosus |
37. Branchlets pale green to grayish green and glaucous; leaf blades flat, margins not wavy; capsule valves crested. | C. lemmonii |