Flora of North America species comparison

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

Ceanothus cuneatus

Ceanothus griseus

buck brush, common buckbrush, narrow-leaf buckthorn, sedge-leaf buckthorn, wedgeleaf cuneatus

Carmel ceanothus
Habit Shrubs, 0.5–3.5 m. Stems erect, ascending, or spreading, not rooting at nodes; branchlets grayish brown to brown, rigid or flexible, glabrate, puberulent, or tomentulose, hairs straight. Shrubs, sometimes arborescent, evergreen, 0.5–4 m. Stems erect, ascending to arcuate, rarely prostrate, not rooting at nodes; branchlets green, not thorn-tipped, angled in cross section, flexible, sparsely puberulent or glabrous.
Leaves

usually both fascicled and not fascicled on same plant, rarely none fascicled;

petiole 1–3 mm;

blade flat to cupped, elliptic, oblanceolate, obovate, or orbiculate, 4–22(–30) × 3–12(–22) mm, base rounded, margins thick, not revolute, entire or denticulate distal to middle, teeth 0–9, apex obtuse, rounded, truncate, or retuse, abaxial surface pale green, glabrate or glabrous, adaxial surface green, glabrous.

petiole 5–10 mm;

blade flat to cupped, ovate to suborbiculate, 10–45 × 10–30 mm, base obtuse to rounded, margins denticulate, ± revolute, teeth 21–45, apex obtuse to rounded, abaxial surface pale green, puberulent to densely villosulous, veins prominently raised, puberulent to villosulous, adaxial surface dark green, glabrate; 3-veined from base.
Inflorescences

axillary or terminal, 0.8–2.5 cm.

axillary, paniclelike, 2–7 cm.
Flowers

sepals, petals, and nectary white to lavender or blue.

sepals, petals, and nectary blue.
Capsules

4–6 mm wide, weakly lobed;

valves smooth, horns subapical, prominent, erect, intermediate ridges absent.

3–4 mm wide, weakly lobed at apex;

valves smooth, viscid, not crested.

Ceanothus cuneatus

Ceanothus griseus
Phenology Flowering Mar–Jun.
Habitat Sandy or rocky flats and slopes, maritime chaparral, open sites in pine and cypress forests.
Elevation 10–200 m. (0–700 ft.)
Distribution
from FNA
CA; OR; nw Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
Discussion

Varieties 4 (4 in the flora).

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

Ceanothus griseus is distributed along the coast from Mendocino County south to Santa Barbara County. Plants with incompletely revolute leaf margins and abaxial surfaces intermediate or similar to those of C. thyrsiflorus are encountered frequently. Whether this pattern is a result of primary or secondary intergradation is not known. Prostrate plants with wide elliptic leaves have been called C. griseus var. horizontalis McMinn; they retain their stature under cultivation. Putative hybrids with C. dentatus have been named C. ×lobbianus Hooker (M. Van Rensselaer and H. McMinn 1942). Ceanothus ×veitchianus Hooker is a rare intersubgeneric hybrid between C. griseus and C. rigidus, first collected by William Lobb near Monterey in 1853, that is cultivated in Great Britain as an ornamental.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Leaf blades of fascicled and non-fascicled leaves elliptic to widely oblanceolate, length usually 2+ times width; sepals, petals, and nectaries usually white, sometimes pale blue or pale lavender.
var. cuneatus
1. Leaf blades of fascicled and non-fascicled leaves widely oblanceolate, widely obovate, or orbiculate, length usually less than 2 times width, or of fascicled leaves elliptic to narrowly oblanceolate (in var. fascicularis); sepals, petals, and nectaries usually lavender to blue, sometimes pale blue, rarely white.
→ 2
2. Leaf blades of fascicled leaves elliptic to narrowly oblanceolate, 9–15 × 3–6 mm, length usually 2+ times width.
var. fascicularis
2. Leaf blades of fascicled leaves widely oblanceolate, widely obovate, or orbiculate, 4–15 × 3–12 mm, length less than 2 times width.
→ 3
3. Leaf blade margins usually entire, rarely 1–4-toothed, apices rounded, truncate, or retuse.
var. ramulosus
3. Leaf blade margins 5–9-toothed, apices rounded to truncate.
var. rigidus
Source FNA vol. 12, p. 99. FNA vol. 12, p. 91.
Parent taxa Rhamnaceae > Ceanothus > subg. Cerastes Rhamnaceae > Ceanothus > subg. Ceanothus
Sibling taxa
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. cordulatus, C. crassifolius, 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. 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. 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. spinosus, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
Subordinate taxa
C. cuneatus var. cuneatus, C. cuneatus var. fascicularis, C. cuneatus var. ramulosus, C. cuneatus var. rigidus
Synonyms Rhamnus cuneata C. thyrsiflorus var. griseus, C. griseus var. horizontalis
Name authority (Hooker) Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 267. (1838) (Trelease) McMinn: in M. van Rensselaer and H. McMinn, Ceanothus, 210. (1942)
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).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:
Northwest Wildflowers