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 cyaneus

Ceanothus prostratus

lakeside ceanothus, San Diego buckbrush

mahala mat, prostrate ceanothus, squawcarpet
Habit Shrubs, evergreen, 2–5 m. Stems erect, not rooting at nodes; branchlets light green, not thorn-tipped, angled in cross section, flexible, often tuberculate (tubercles minute, brownish), puberulent, glabrescent. Shrubs, 0.1–0.3 m, matlike to moundlike.
Stems

prostrate, spreading, or ascending, rooting at distal nodes;

branchlets reddish brown, ± flexible, puberulent, glabrescent.
Leaves

petiole 2–6 mm;

blade flat, ovate-elliptic, 20–50 × 15–20 mm, base rounded, margins usually denticulate to serrulate, rarely entire, not revolute, teeth 23–58, apex acute to obtuse, abaxial surface pale green, veins puberulent, adaxial surface dark green, glabrous or sparsely puberulent; 3-veined from base.

not fascicled, crowded, usually longer than internodes and obscuring them;

petiole 1–3 mm;

blade flat to ± cupped, elliptic to obovate, 6–30 × 4–16 mm, base cuneate, margins sometimes thick, not revolute, sometimes wavy, sharply dentate to spinose-dentate, teeth 3–9, apex rounded, abaxial surface pale green, glabrous except sparsely strigillose on veins, adaxial surface dark green, shiny, glabrate.
Inflorescences

terminal, paniclelike, 15–30(–40) cm.

axillary, 0.9–2 cm.
Flowers

sepals, petals, and nectary deep blue.

sepals, petals, and nectary pale to deep blue or purplish blue.
Capsules

3–5 mm wide, deeply lobed;

valves smooth, weakly crested.

6–9 mm wide, lobed;

valves smooth to rugulose, horns subapical, prominent, erect or spreading, rugose or not, intermediate ridges present.
2n

= 24.

= 24.

Ceanothus cyaneus

Ceanothus prostratus
Phenology Flowering Apr–Jun.
Habitat Rocky or gravelly slopes, chaparral.
Elevation 40–600 m. (100–2000 ft.)
Distribution
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; NV; OR; WA
[WildflowerSearch map]
[BONAP county map]
Discussion

Ceanothus cyaneus is known in the flora area only from San Diego County, and is threatened throughout its range.

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

Varieties 2 (2 in the flora).

Putative hybrids between Ceanothus prostratus and C. velutinus var. velutinus, named C. ×rugosus, have been reported from northeastern California (H. McMinn 1944). A rare putative hybrid between C. prostratus and C. cordulatus in the Lake Tahoe basin has been named C. ×serrulatus. Both C. ×rugosus and C. ×serrulatus are intersubgeneric hybrids. Formally named hybrids between C. prostratus and C. cuneatus var. cuneatus include C. ×flexilis and possibly C. ×connivens, but the latter could have C. fresnensis as one of the parents rather than C. prostratus.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Leaf blades flat, margins not wavy, teeth usually 3–5(–7); capsule horns erect.
var. prostratus
1. Leaf blades slightly folded lengthwise adaxially, margins ± wavy, teeth 5–9; capsule horns spreading.
var. occidentalis
Source FNA vol. 12, p. 90. FNA vol. 12, p. 104.
Parent taxa Rhamnaceae > Ceanothus > subg. Ceanothus Rhamnaceae > Ceanothus > subg. Cerastes
Sibling taxa
C. americanus, C. arboreus, C. arcuatus, C. confusus, C. cordulatus, C. crassifolius, C. cuneatus, 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. 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. pumilus, C. purpureus, C. roderickii, C. sanguineus, C. sonomensis, C. spinosus, C. thyrsiflorus, C. tomentosus, C. velutinus, C. verrucosus
Subordinate taxa
C. prostratus var. occidentalis, C. prostratus var. prostratus
Name authority Eastwood: Proc. Calif. Acad. Sci., ser. 4, 16: 361. (1927) Bentham: Pl. Hartw., 302. (1849)
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