Rhamnus crocea |
Rhamnus serrata |
|
---|---|---|
hollyleaf buckthorn, redberry, redberry buckthorn, spiny redberry |
sawleaf buckthorn |
|
Habit | Shrubs, 1.2–2(–4) m, usually armed with thorns. | Shrubs to small trees, 0.8–2.5 m, unarmed. |
Branchlets | reddish to red-purple or orange-brown; glabrous. |
gray-brown, 2 cm, puberulent, glabrescent. |
Leaves | persistent, alternate; petiole 2–6 mm; blade usually dull green abaxially, shiny dark green adaxially, elliptic to obovate or ovate, 0.7–2 cm, distinctly coriaceous, base cuneate to truncate, margins coarsely serrate, spinulose-serrulate, or entire, apex obtuse to emarginate, both surfaces glabrous; secondary veins 5–7 pairs, all diverging at nearly same angle. |
deciduous, alternate to subopposite; petiole 3–4 mm; blade usually yellowish brown, rarely green, abaxially, green adaxially, elliptic to elliptic-lanceolate or elliptic-oblong, 1.5–5(–5.5) cm, herbaceous, base cuneate to rounded or truncate, margins serrulate to crenulate, apex obtuse, both surfaces minutely hirtellous, often more densely so abaxially; secondary veins 5–8(–11) pairs, all diverging at nearly same angle. |
Inflorescences | fascicles or flowers solitary. |
fascicles or flowers solitary. |
Pedicels | 2–3 mm. |
1–4 mm. |
Drupes | red, globose, 5–8 mm; stones 2. |
black, globose or slightly elongate, 4–6(–8) mm; stones 2. |
Sepals | 4(–5). |
4. |
Petals | 0. |
4. |
Bud | scales dark red to reddish brown, coriaceous, dull. |
|
Rhamnus crocea |
Rhamnus serrata |
|
Phenology | Flowering (Jan–)Mar–May. | Flowering Apr–Jun. |
Habitat | Dry washes and canyons, coastal and inland dunes, alluvial fans, gravel flood plains, disturbed sandy flats, brushy slopes, steep granitic slopes, woodlands, coastal sage scrub, chaparral. | Canyons, stream banks, open hillsides, ledges, ridges, among boulders, gravelly limestone hills, roadsides, mesic forests, woodlands. |
Elevation | 50–1200 m. (200–3900 ft.) | 1500–2600 m. (4900–8500 ft.) |
Distribution |
CA
|
AZ; NM; TX; Mexico; Central America (Guatemala) |
Discussion | Rhamnus crocea and closely related species were considered conspecific by C. B. Wolf (1938), who treated those in the flora area as subspp. crocea, ilicifolia, pilosa, and pirifolia; he also recognized subsp. insula (Kellogg) C. B. Wolf from Mexico (Baja California). The taxa are distinctive, but intermediates exist. Wolf identified R. crocea/ilicifolia intermediates from Marin County to the California/Mexico boundary, and R. ilicifolia/insula, R. crocea/pilosa, and R. ilicifolia/pilosa intermediates in southern California, especially in San Diego County. Arizona plants (Pima County, especially in the Ajo Mountains) identified as Rhamnus crocea (for example, K. Christie 2006) appear to be populational variants of the single species present there, R. ilicifolia (R. Felger, pers. comm.). In California, where the two are sympatric over a relatively broad region, R. crocea is distinct from R. ilicifolia in usually bearing thorns and in having smaller leaves with less spinulose margins. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 47. | FNA vol. 12, p. 49. |
Parent taxa | Rhamnaceae > Rhamnus | Rhamnaceae > Rhamnus |
Sibling taxa | ||
Synonyms | R. fasciculata, R. serrata var. guatemalensis, R. smithii subsp. fasciculata | |
Name authority | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 261. (1838) — (as croceus) | Humboldt & Bonpland ex Willdenow: in J. J. Roemer et al., Syst. Veg. 5: 295. (1819) |
Web links |