Flora of North America species comparison

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Ceanothus papillosus

Ceanothus palmeri

wartleaf ceanothus

Palmer ceanothus, Palmer's 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, evergreen or semideciduous, 1–2 m. Stems ascending to erect, not rooting at nodes; branchlets green or gray-green, not thorn-tipped, round in cross section, flexible or rigid, glabrous or glabrate.
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.

not fascicled;

petiole 3–8 mm;

blade ± cupped, elliptic, oblong, or oblong-ovate, 13–30 × 9–15 mm, base cuneate to obtuse, margins entire, apex acute to rounded, abaxial surface pale green, glabrous, adaxial surface green, dull to ± shiny, glabrous; usually pinnately veined, rarely 3-veined.
Inflorescences

axillary or terminal, racemelike, 2–8 cm.

terminal or axillary, paniclelike, 7.5–22 cm.
Flowers

sepals, petals, and nectary deep blue.

sepals, petals, and nectary usually white, rarely pale blue.
Capsules

2–3 mm wide, lobed;

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

4.5–7 mm wide, lobed;

valves smooth, viscid, crested.
2n

= 24.

Ceanothus papillosus

Ceanothus palmeri
Phenology Flowering Mar–May. Flowering Mar–Jun.
Habitat Rocky ridges, slopes, and flats, chaparral, mixed evergreen forests. Rocky slopes, chaparral, conifer forests.
Elevation 20–1500 m. (100–4900 ft.) 1100–1800 m. (3600–5900 ft.)
Distribution
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[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.)

Ceanothus palmeri occurs in the Transverse and Peninsular ranges of California, with a disjunct distribution in the central Sierra Nevada foothills (Amador and El Dorado counties). Ceanothus palmeri appears to be closely related to and intermediate between C. integerrimus and C. spinosus (W. L. Jepson 1909–1943, vol. 2; M. Van Rensselaer and H. McMinn 1942). We treat this species as distinct from C. spinosus on the basis of its white flowers, and viscid, lobed fruit, but note that some populations intergrade, especially in the Transverse Ranges of southern California. Leaf blades of both C. palmeri and C. spinosus have somewhat shiny adaxial faces, but those of C. integerrimus appear dull. Included here are plants with weakly three-veined leaf blades with somewhat shiny adaxial surfaces from the Transverse Ranges, previously treated by Van Rensselaer and McMinn as part of C. integerrimus.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 12, p. 92. FNA vol. 12, p. 86.
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. microphyllus, C. oliganthus, C. ophiochilus, C. otayensis, 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. spinosus var. palmeri
Name authority Torrey & A. Gray: Fl. N. Amer. 1: 268. (1838) Trelease: Proc. Calif. Acad. Sci., ser. 2, 1: 109. (1888)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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