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

green-bark ceanothus, redheart

littleleaf buckbrush, sandflat ceanothus

Habit Shrubs, sometimes arborescent, evergreen, 2–6 m. Stems erect, not rooting at nodes; branchlets green, thorn-tipped or not, round to ± angled in cross section, rigid, glabrous or sparsely puberulent. Shrubs, deciduous, 0.4–0.7 m. Stems erect to ascending, not rooting at nodes; branchlets reddish green or yellow-green, not thorn-tipped, round in cross section, flexible, usually puberulent, sometimes strigillose.
Leaves

not fascicled;

petiole 4–7 mm;

blade ± cupped, elliptic to oblong, 11–35 × 8–29 mm, base cuneate to rounded, margins entire, apex obtuse to weakly retuse, abaxial surface pale green, not glaucous, sometimes puberulent on midribs, adaxial surface green, shiny, glabrous; pinnately veined.

often fascicled;

petiole 0.5–1 mm;

blade flat, elliptic, ovate-elliptic, or narrowly obovate, 2–10 × 1–6 mm, base cuneate, margins entire or weakly denticulate distally, not wavy, teeth 5–9, apex rounded or obtuse, abaxial surface pale green, puberulent on veins, adaxial surface green, glabrous; pinnately veined or 3-veined from base (venation obscure).

Inflorescences

axillary, paniclelike, 4–17 cm.

axillary or terminal, umbel-like or ± racemelike, 1–3 cm.

Flowers

sepals, petals, and nectary pale blue to blue.

sepals, petals, and nectary white.

Capsules

4–6 mm wide, not lobed;

valves smooth, not conspicuously viscid, not or weakly crested.

3–4.5 mm wide, lobed;

valves smooth, not crested.

2n

= 24.

Ceanothus spinosus

Ceanothus microphyllus

Phenology Flowering Jan–May. Flowering Mar–Jun.
Habitat Rocky slopes, coastal sage scrub, chaparral. Sandy flats, shrublands, pine-oak woodlands.
Elevation 60–900 m. (200–3000 ft.) 0–200 m. (0–700 ft.)
Distribution
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA
[WildflowerSearch map]
[BONAP county map]
Discussion

Like Ceanothus incanus, plants of C. spinosus are polymorphic for the presence of thorn-tipped branchlets. Putative hybrids with C. thyrsiflorus and C. oliganthus var. sorediatus have been reported (M. Van Rensselaer and H. McMinn 1944).

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

Short-statured plants of Ceanothus microphyllus with ovate-elliptic leaves, evident venation, and racemelike inflorescences have been called C. serpyllifolius (M. Van Rensselaer and H. McMinn 1942; W. H. Duncan and J. T. Kartesz 1981). Ceanothus serpyllifolius is treated here as part of C. microphyllus, because of continuous variation in leaf size, shape, and inflorescence architecture. Ceanothus serpyllifolius also has been applied to small-leaved, short-statured plants of C. americanus, some of which may be hybrids between that species and C. microphyllus (N. C. Coile 1988).

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

Source FNA vol. 12, p. 86. FNA vol. 12, p. 83.
Parent taxa Rhamnaceae > Ceanothus > subg. Ceanothus Rhamnaceae > Ceanothus > subg. Ceanothus
Sibling taxa
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. cordulatus, C. crassifolius, C. cuneatus, C. cyaneus, C. dentatus, C. divergens, C. diversifolius, C. fendleri, C. ferrisiae, C. foliosus, C. fresnensis, C. gloriosus, C. griseus, C. hearstiorum, C. herbaceus, C. impressus, C. incanus, C. integerrimus, C. jepsonii, C. lemmonii, C. leucodermis, C. maritimus, C. martini, C. masonii, C. megacarpus, C. microphyllus, C. oliganthus, C. ophiochilus, C. otayensis, C. palmeri, C. papillosus, C. parryi, C. parvifolius, C. pauciflorus, C. perplexans, C. pinetorum, C. prostratus, C. pumilus, C. purpureus, C. roderickii, C. sanguineus, C. sonomensis, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. cordulatus, C. crassifolius, C. cuneatus, C. cyaneus, C. dentatus, C. divergens, C. diversifolius, C. fendleri, C. ferrisiae, C. foliosus, C. fresnensis, C. gloriosus, C. griseus, C. hearstiorum, C. herbaceus, C. impressus, C. incanus, C. integerrimus, C. jepsonii, C. lemmonii, C. leucodermis, C. maritimus, C. martini, C. masonii, C. megacarpus, C. oliganthus, C. ophiochilus, C. otayensis, C. palmeri, C. papillosus, C. parryi, C. parvifolius, C. pauciflorus, C. perplexans, C. pinetorum, C. prostratus, C. pumilus, C. purpureus, C. roderickii, C. sanguineus, C. sonomensis, C. spinosus, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
Synonyms C. serpyllifolius
Name authority Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 267. (1838) Michaux: Fl. Bor.-Amer. 1: 154. (1803)
Web links