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wartleaf ceanothus

littleleaf buckbrush, sandflat ceanothus

Habit Shrubs, evergreen, 1–5 m. Stems erect to ascending, not rooting at nodes; branchlets green to reddish brown, not thorn-tipped, round in cross section, ± flexible to rigid, densely tomentulose. 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

petiole 1–3 mm;

blade cupped to flat, linear, narrowly oblong, or oblong-elliptic, 12–50 × 6–15 mm, base obtuse to rounded, margins minutely glandular-denticulate, revolute, glands 17–31, apex obtuse, truncate, or retuse, abaxial surface pale green, densely villosulous to tomentulose, adaxial surface dark green, sparsely puberulent and glandular-papillate; 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 or terminal, racemelike, 2–8 cm.

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

Flowers

sepals, petals, and nectary deep blue.

sepals, petals, and nectary white.

Capsules

2–3 mm wide, lobed;

valves smooth, viscid when young, not or weakly crested.

3–4.5 mm wide, lobed;

valves smooth, not crested.

2n

= 24.

Ceanothus papillosus

Ceanothus microphyllus

Phenology Flowering Mar–May. Flowering Mar–Jun.
Habitat Rocky ridges, slopes, and flats, chaparral, mixed evergreen forests. Sandy flats, shrublands, pine-oak woodlands.
Elevation 20–1500 m. (100–4900 ft.) 0–200 m. (0–700 ft.)
Distribution
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA
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[BONAP county map]
Discussion

Ceanothus papillosus occurs in the Coast Ranges from San Francisco Bay south to the Santa Ynez Mountains, Ventura County, with disjunct populations in the Santa Ana Mountains, California, and Cerro Bola, in northern Baja California. The name C. papillosus var. roweanus was originally applied to low-growing plants with ascending to spreading, arcuate branches (H. McMinn 1939). M. Van Rensselaer and McMinn (1942) later emended the circumscription to include plants with linear leaves and retuse to truncate leaf apices, but these are found throughout the range of the species. Leaves with obtuse to truncate or retuse leaf apices also can be found on the same plant. Putative hybrids with C. integerrimus and C. oliganthus have been documented (McMinn 1944). Hybrids with C. thyrsiflorus have been named C. ×regius (Jepson) McMinn. Some putatively advanced generation hybrids have narrowly elliptic, weakly papillate leaves with obtuse apices, and sometimes have been misinterpreted as belonging to C. papillosus.

(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. 92. 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. 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
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. papillosus subsp. roweanus, C. papillosus var. roweanus C. serpyllifolius
Name authority Torrey & A. Gray: Fl. N. Amer. 1: 268. (1838) Michaux: Fl. Bor.-Amer. 1: 154. (1803)
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