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Key to Groups and to Species

A. Nutlets not grooved in front.

B. Leaf veins extending to points of lobes; not to sinuses.

C. Petioles short; leaves obovate, wedge shaped at base.

D. Corymbs many-flowered.

E. Leaves leathery, dark green, shining above; fruit almost globular, nutlets 1 to 3, ridged on back.

I. Group CRUS-GALLI

F. Stamens 10, anthers rose colour; leaves thick, fruit dull red; spines stout, 4 to 6 inches long.

(C. Crus-galli) COCKSPUR THORN

FF. Stamens 20, anthers yellow; leaves thin; fruit orange red; spines slender, 1 to 1 1/2 inches long.

(C. Mobri) HAW

EE. Leaves membranaceous or firm; veins strong; fruit usually dotted; nutlets 2 to 5, strongly ridged on back.

II. Group PUNCTATAE

F. Fruit oblong, yellow or red, 1/2 to 1 inch long, with large, pale dots; stamens 20.

(C. punctata) DOTTED HAW

FF. Fruit globose, 1/3 to 1/2 inch long, dull red, with small pale dots; stamens 20, yellow.

(C. collina) HAW

DD. Corymbs few-flowered; flowers with leaves in February, stamens 20 to 25, with large, dark-red anthers.

III. Group AESTIVALES

(C. aestivalis) MAY HAW

CC. Petioles long, slender, scarcely glandular; leaves mem-branaceous to leathery, narrow at base; corymbs many-flowered; fruit oblong to subglobose, 1/8 to 5/8 inches in diameter.

IV. Group VIRIDES

Fruit flattened, under 1/3 inch in diameter, bright scarlet or orange.

(C. viridis) HAW

CCC. Petioles long, slender, glandular at apex.

D. Leaves broad at base; corymbs many-flowered.

E. Fruit flattened, 1/2 to 5/8 inch in diameter, green, with glaucous bloom, becoming dark purple-red and lustrous; leaves blue green, smooth.

V. Group PRUINOSAE

Leaves elliptical

(C. pruinosa) HAW

EE. Fruit short oblong or obovate, 1/2 to 5/8 inch long, scarlet to purple, leaves mem-branaceous.

VI. Group TENUIFOLIA

Leaves blue-green, rough.

(C. apiomorpha) HAW

EEE. Fruit 1 inch in diameter, red or yellow, flesh thick, juicy; corymbs downy.

VII. Group MOLLES

F. Stamens 20, anthers yellow; leaves broad and thick; fruit scarlet, downy.

(C. mollis) RED HAW

FF. Stamens 10, anthers yellow.

G. Fruit crimson, velvety, flattened.

(C. Arnoldiana) SCARLET HAW

GG. Fruit orange red, lustrous.

(C. submollis) RED HAW

FFF. Stamens 10, anthers rose colour.

Fruit short oblong, bright crimson, shining.

(C. Ellwangeriana) SCARLET HAW

EEEE. Fruit oblong, 3/4 inch long, red, pulpy, lustrous; leaves lobed; anthers red.

VIII. Group FLABELLATAE

Stamens 5, rarely 6 to 8; leaves yellow-green.

(C. Holmesiana) HAW

EEEEE. Fruit nearly round, 3/4 inch long, greenish red, calyx prominent; stamens 20, anthers rose coloured.

IX. Group DILATATAE

Flowers 1 1/4 inches across, few; leaves 2 to 3 inches long and broad, with deep side lobes.

(C. coccinioides) HAW

DD. Leaves wedge shaped at base.

E. Corymbs many-flowered; leaves dark green, lustrous above, fruit 1/2 to 3/4 inch long, nutlets 2 to 3, ridged on back.

X. Group COCCINEAE

Thorns 1 1/2 inch long, brown, stout; fruit crimson, dry and sweet, leaves 2 to 3 inches long.

(C. coccinea) SCARLET HAW

EE. Corymbs few-flowered; leaves membranaceous.

F. Fruit 1/2 inch long, green or yellow; nutlets 3 to 5, rounded at ends, strongly ridged at back; leaves yellow-green.

XI. Group INTRICATAE

Fruits 2 to 4 in clusters, erect, flat, rusty, reddish green, stamens 10, pale yellow.

(C. Boyntoni) HAW

FF. Fruit 1/4 inch long, red or orange; nutlets 3 to 5 but slightly grooved on back; stamens 20, anthers rose coloured; leaves thin, sharply lobed.

XII. Group PULCHERRIMAE

Fruit bright red.

(C. opima) HAW

FFF. Fruit 1/2 to 5/8 inch long; nutlets 3 to 5, narrowed at ends, strongly ridged on back; bracts large; calyx lobes leaf-like; stamens 20, anthers yellow; leaves dark, lustrous, leathery.

XIII. Group BRACTEATAE

Fruit bright red.

(C. Ashei) HAW

CCCC. Petioles, leaves and corymbs conspicuously glandular; corymbs few-flowered; fruit 1/2 to 3/4 inch long, flesh hard, dry; branches zizag.

XIV. Group FLAVAE

Bark deeply furrowed; leaves diamond shaped, thick, shining, with short winged petiole; corymbs velvety, with 3 to 6 flowers, stamens 10, anthers yellow; fruit late, dull orange red, flattened.

(C. aprica) HAW

BB. Veins of leaves extending to sinuses as well as to points of lobes; corymbs many-flowered; stamens 20.

C. Fruit flattened to oblong, pea size, scarlet; nutlets 2 to 5, prominently ridged at back; anthers rose coloured or purple.

XV. Group MICROCARPAE

D. Leaves round, deeply 5 to 7 cleft.

(C. apiifolia) PARSLEY HAW

DD. Leaves heart shaped.

(C. cordata) WASHINGTON THORN

CC. Fruit flattened, 1/3 to 1/2 inch long, red, blue or blue-black nutlets 3 to 5, obtuse at ends, slightly ridged at back; leaves dark and lustrous.

XVI. Group BRACHYACANTHAE

Leaves lanceolate; thorns stout; fruit bright blue.

(C. brachyacantha) POMETTE BLEUE

AA. Nutlets grooved in front.

B. Fruits 1/4 to 1/2 inch long, erect, lustrous, orange or scarlet; nutlets 2 to 3, blunt at ends, ridged on back; leaves downy below.