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

evergreen buckthorn, holly leaf redberry, redberry

buckthorn, cascara, nerprun

Habit Shrubs or small trees, 1–4 m, unarmed. Shrubs or trees, erect or spreading, unarmed or armed with thorns; bud scales present, buds glabrate.
Branchlets

gray, stiff, glabrous or densely and softly hirtellous.

Leaves

persistent, alternate;

petiole 2–10 mm;

blade usually dull green, sometimes reddish brown, abaxially, glossy to dull green adaxially, broadly elliptic to oblong, orbiculate, or ovate, 2–4.5 cm, distinctly coriaceous, base cuneate to nearly truncate, margins spinulose to spinose-dentate, apex rounded or obtuse to truncate or emarginate, both surfaces glabrous;

secondary veins 5–7 pairs, all diverging at nearly same angle.

deciduous or persistent, present at flowering, alternate or opposite to subopposite, sometimes fascicled on short shoots;

blade not gland-dotted; pinnately veined, secondary veins arching, not parallel.

Inflorescences

fascicles or flowers solitary.

axillary, within foliage, fascicles or cymes, or flowers solitary;

peduncles and pedicels not fleshy in fruit.

Pedicels

2–4 mm.

present.

Flowers

usually unisexual, rarely some bisexual (plants polygamous);

hypanthium campanulate to cupulate, 2–3 mm wide, usually not circumscissile, rarely so at or just proximal to sepal bases;

sepals 4–5, spreading, yellowish, yellowish green, green, or greenish white to white, ovate-triangular, thin, not keeled or crested adaxially;

petals 0 or 4[–5], yellowish to cream, hooded, spatulate, not clawed;

nectary thin, lining hypanthium;

stamens 4–5, (rudimentary in pistillate flowers);

ovary superior, 2–4-locular;

styles 2–4, connate proximally.

Fruits

drupes;

stones 2–4, longitudinally dehiscent.

Drupes

red, globose, 4–6(–8) mm;

stones 2.

Seeds

obovoid or oblong-obovoid, not beaked, longitudinally furrowed.

Sepals

4.

Petals

0.

x

= 12.

2n

= 24.

Rhamnus ilicifolia

Rhamnus

Phenology Flowering Jan–Jun.
Habitat Canyon slopes and bottoms, rock faces, open hillsides, sandstone ridges, serpentine slopes, roadsides, stream benches, riparian areas, meadows, coastal sage scrub, chaparral/desert transition, chaparral, woodlands, montane forests.
Elevation 100–2200(–2400) m. (300–7200(–7900) ft.)
Distribution
from FNA
AZ; CA; NV; OR; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from USDA
North America; Mexico; Central America; South America; Europe; e Asia; Africa
[BONAP county map]
Discussion

Species ca. 150 (14 in the flora).

Rhamnus in the flora area includes six species (species 9–14) introduced primarily from Europe and Asia. The native species for the most part are clearly delimited, but the R. crocea complex needs taxonomic study using modern techniques.

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

Key
1. Leaves persistent, alternate, blades distinctly coriaceous; petals 0 (rarely 4 in R. pilosa).
→ 2
2. Leaf blade secondary veins with basal pair diverging much more acutely than distal pairs; inflorescences cymes or flowers solitary; sepals 5; drupes dark red, becoming black, stones 3.
R. alaternus
2. Leaf blade secondary veins all diverging at nearly same angle; inflorescences fascicles or flowers solitary; sepals 4(–5); drupes red, stones 2.
→ 3
3. Leaf blade margins entire or coarsely serrate, blunt-serrate, or spinulose-serrate.
→ 4
4. Shrubs, 1.2–2(–4) m, usually armed with thorns; leaf blades 0.7–2 cm, elliptic to obovate or ovate; California mainland.
R. crocea
4. Shrubs or trees, 2.5–6(–10) m, unarmed; leaf blades (1.5–)2–5(–6) cm, broadly elliptic to oblong or ovate-oblong; California Channel Islands.
R. pirifolia
3. Leaf blade margins spinulose to spinose-dentate.
→ 5
5. Branchlets stiff, glabrous or densely and softly hirtellous; both leaf blade surfaces glabrous.
R. ilicifolia
5. Branchlets flexible, sparsely to densely softly hirtellous; both leaf blade surfaces sparsely to densely softly hirtellous.
R. pilosa
1. Leaves deciduous, alternate, subopposite, or opposite, sometimes fascicled on short shoots, blades herbaceous to subcoriaceous; petals 0 or 4.
→ 6
6. Leaves usually alternate, sometimes subopposite, blade secondary veins 4–11 pairs; shrubs or small trees 0.5–3(–4) m, unarmed.
→ 7
7. Sepals 5; petals 0; drupe stones 3; shrubs 0.5–1(–1.5) m; wetlands and seeps.
R. alnifolia
7. Sepals 4; petals 4; drupe stones 2 (3 in R. arguta); shrubs or small trees 0.5–3(–4) m; drier habitats.
→ 8
8. Petioles 10–28 mm; pedicels 10–24(–30) mm; drupe stones 3; leaf blades usually broadly ovate, ovate, oblong-ovate, or ovate-cordate, sometimes ovate-orbiculate, margins spinulose-serrate.
R. arguta
8. Petioles 3–8 mm; pedicels (0–)0.5–4 mm; drupe stones 2; leaf blades lanceolate, elliptic-lanceolate, oblong-lanceolate, elliptic, or elliptic-oblong, margins crenulate, crenulate-serrate, or serrulate.
→ 9
9. Branchlets 6+ cm; leaf blade apices acute to acuminate; c, e United States.
R. lanceolata
9. Branchlets 2–5 cm; leaf blade apices acute to obtuse or rounded; w United States.
→ 10
10. Bud scales thin, glossy, pale golden to yellowish; leaf blades usually lanceolate, sometimes elliptic-lanceolate or oblong-lanceolate, 3–8 cm, both surfaces glabrous.
R. smithii
10. Bud scales coriaceous, dull, dark red to reddish brown; leaf blades usually elliptic to elliptic-lanceolate or elliptic-oblong, 1.5–5(–5.5) cm, both surfaces minutely hirtellous.
R. serrata
6. Leaves usually opposite to subopposite, sometimes alternate or fascicled on short shoots, blade secondary veins 2–7(–8) pairs; shrubs or trees (1–)2–10 m, armed with thorns.
→ 11
11. Leaf blade bases rounded to truncate or cordate; drupe stones 3–4.
→ 12
12. Leaf blade margins crenate-serrate, secondary veins 2–4 pairs; pedicels 2–4 mm; drupes 5–6(–8) mm.
R. cathartica
12. Leaf blade margins spinulose-serrate, secondary veins (3–)4–5 pairs; pedicels 10–24(–30) mm; drupes 7–10 mm.
R. arguta
11. Leaf blade bases cuneate or acute; drupe stones 2.
→ 13
13. Leaf blades obovate to elliptic-oblanceolate or broadly oblanceolate, adaxial surfaces usually minutely hirtellous at least along main veins on distal 1/3, rarely glabrous.
R. japonica
13. Leaf blades usually elliptic to oblong, oblong-obovate, obovate-elliptic, or oblong-lanceolate, sometimes ovate to obovate, rarely oblanceolate-elliptic, adaxial surfaces glabrous or sparsely pilose on veins.
→ 14
14. Leaf blades green abaxially, abaxial surface with straight, colorless hairs on veins, secondary veins 3–5(–6) pairs; pedicels 10–20 mm.
R. davurica
14. Leaf blades yellowish green abaxially, abaxial surface with wavy or curled, yellow hairs along veins or at least in vein axils, secondary veins (4–)5–7(–8) pairs; pedicels 5–10 mm.
R. utilis
Source FNA vol. 12, p. 48. FNA vol. 12, p. 45. Authors: Guy L. Nesom, John O. Sawyer†.
Parent taxa Rhamnaceae > Rhamnus Rhamnaceae
Sibling taxa
R. alaternus, R. alnifolia, R. arguta, R. cathartica, R. crocea, R. davurica, R. japonica, R. lanceolata, R. pilosa, R. pirifolia, R. serrata, R. smithii, R. utilis
Subordinate taxa
R. alaternus, R. alnifolia, R. arguta, R. cathartica, R. crocea, R. davurica, R. ilicifolia, R. japonica, R. lanceolata, R. pilosa, R. pirifolia, R. serrata, R. smithii, R. utilis
Synonyms R. crocea subsp. ilicifolia, R. crocea var. ilicifolia
Name authority Kellogg: Proc. Calif. Acad. Sci. 2: 37. (1863) — (as ilicifolius) Linnaeus: Sp. Pl. 1: 193. (1753): Gen. Pl. ed. 5, 89. (1754)
Web links