Cratægus is most abundant in eastern North America, where it is distributed from Newfoundland to the mountains of northern Mexico, and is represented by a large number of arborescent and shrubby species. A few species occur in the Rocky Mountains and Pacific-coast regions, and in China, Japan, Siberia, central and southwestern Asia, and in Europe. The genus is still very imperfectly known in North America, and in the absence of sufficient information concerning them several arborescent species are necessarily excluded from the following enumeration. The beautiful and abundant flowers and showy fruits make many of the species desirable ornaments of parks and gardens, and several are cultivated. Of exotic species, the Old World Cratægus Oxyacantha L., and C. monogyna Jacq., early introduced into the United States as hedge plants, have now become naturalized in many places in the northeastern and middle states. Cratægus produces heavy hard tough close-grained red-brown heartwood and thick lighter colored usually pale sapwood; useful for the handles of tools, mallets, and other small articles.
The number of the stamens, although it differs on the same species within certain usually constant limits, and the color of the anthers, which appears to be specifically constant with one exception, afford the most satisfactory characters for distinguishing the species in the different groups.
Cratægus, from κράτος, is in reference to the strength of the wood of these trees.
CONSPECTUS OF THE NATURAL GROUPS OF THE NORTH AMERICAN ARBORESCENT SPECIES.
1. Nutlets without ventral cavities. *Veins of the leaves extending to the points of the lobes only. †Petioles short, usually slightly wing-margined above the middle, glandless or with occasional minute glands; leaves cuneate at base. Corymbs compound, generally many-flowered; flowers appearing after the unfolding of the leaves; flesh of the fruit usually green or greenish yellow, dry and mealy. Leaves coriaceous or subcoriaceous, rarely thin, dark green and shining above, usually serrate only above the middle, their veins thin except on vigorous shoots; fruit mostly subglobose to short-oblong; nutlets 1—5, thick, usually obtuse and rounded at the ends, prominently ridged on the back.I. Crus-galli ([page 400]). Leaves membranaceous or subcoriaceous, mostly acute, their veins prominent; fruit short-oblong to subglobose, often conspicuously punctate, ⅓′—1′ long; nutlets 2—5, prominently ridged on the back.II. Punctatæ ([page 422]). Corymbs simple, few-flowered; flowers appearing with or before the unfolding of the leaves; fruit scarlet, lustrous; flesh yellow, juicy, subacid; nutlets rounded and slightly grooved on the back.III. Æstivales ([page 434]). †Petioles elongated, slender, eglandular or occasionally glandular; corymbs many-flowered (few-flowered in one species each of Dilatatæ and Intricatæ). ++Leaves acute or acuminate at the ends, broad at base on one species; fruit not more than ⅝′ in diameter; flesh usually thin and dry.IV. Virides ([page 437]). ++Leaves usually broad at base. Fruit subglobose to short-oblong, often broader than high, red or green, often slightly 5-angled, pruinose; mature calyx raised on a short tube; flesh of the fruit dry and mealy; nutlets 5, grooved on the back.V. Pruinosæ ([page 449]). Fruit subglobose to short-oblong, ovoid or obovoid, generally longer than broad, rarely slightly pruinose, mature calyx sessile; flesh of the fruit dry and mealy; stamens 10, anthers rose color; leaves hairy above early in the season.VI. Silvicolæ ([page 453]). Fruit short-oblong to obovoid, red or scarlet; flesh of the fruit usually soft and juicy; anthers rose color or pink; leaves thin, at maturity glabrous below.VII. Tenuifoliæ ([page 456]). Fruit subglobose, oblong or obovoid, crimson, scarlet, or rarely yellow; flesh thick, occasionally succulent, and edible; nutlets usually 5, thin, pointed at the ends, mostly obscurely grooved or ridged on the back; corymbs tomentose or pubescent; leaves membranaceous to subcoriaceous, broad, rounded or cuneate at base, at maturity usually pubescent or tomentose below.VIII. Molles ([page 463]). Fruit short-oblong to obovoid, scarlet; flesh usually soft and juicy; nutlets 3—5, grooved and usually ridged on the back; corymbs glabrous or tomentose; leaves thin or rarely subcoriaceous, oblong-ovate or oval, more or less acutely lobed; anthers rose or purple; rarely white in shrubby species.IX. Coccineæ ([page 488]). Fruit subglobose to short-oblong, crimson, or red tinged with green, its calyx enlarged and prominent; nutlets 5; stamens 20; anthers rose color; leaves thin, at the end of vigorous shoots as broad or broader than long.X. Dilatatæ ([page 500]). ++Leaves cuneate at base. Corymbs many-flowered; leaves subcoriaceous; fruit subglobose, rarely short-oblong; nutlets 2 or 3, obtuse at the ends, conspicuously ridged on the back; corymbs glabrous or tomentose; leaves dark green and lustrous above.XI. Rotundifoliæ ([page 504]). Corymbs few-flowered (many-flowered in one species of Bracteatæ). Fruit subglobose to short-oblong, greenish or yellowish; nutlets 3—5, usually rounded at the ends, conspicuously ridged on the back; leaves subcoriaceous, yellow-green.XII. Intricatæ ([page 508]). Fruit subglobose, red or orange-red; nutlets 3—5, slightly grooved on the back; stamens 20; anthers rose color; leaves thin, incisely lobed.XIII. Pulcherrimæ ([page 511]). Fruit subglobose to short-oblong, ½′—⅝′ long; nutlets 3—5, narrowed at the ends, prominently ridged on the back; corymbs villose; bracts large and conspicuous; calyx-lobes foliaceous; stamens 20; anthers yellow; leaves dark green, lustrous and scabrate above, their petioles sparingly glandular through their whole length.XIV. Bracteatæ ([page 513]). †Petioles long or short, leaves and corymbs glandular; corymbs usually simple, few-flowered; fruit subglobose to short-oblong or obovoid, green, orange, or red, flesh usually hard and dry; branchlets conspicuously zigzag.XV. Flavæ ([page 515]). **Veins of the leaves extending to the points of the lobes and to the sinuses; corymbs many-flowered; stamens usually 20. Fruit depressed-globose to short-oblong, not more than ¼′ long, scarlet; nutlets 2—5, prominently ridged and often grooved on the back; anthers rose color or yellow.XVI. Microcarpæ ([page 530]). Fruit subglobose, ⅓′—½′ in diameter, blue or blue-black; nutlets 3—5, obtuse at the ends, slightly ridged on the back; anthers yellow; leaves cuneate at base, dark green and lustrous.XVII. Brachyacanthæ ([page 533]). 2. Nutlets longitudinal cavities on their ventral faces; flowers in many flowered compound corymbs. Fruit obovoid to subglobose or short-oblong, lustrous, orange or scarlet; nutlets 2 or 3, obtuse at the ends, prominently ridged on the back; leaves thin to subcoriaceous, mostly pubescent below.XVIII. Macracanthæ ([page 535]). Fruit short-oblong to subglobose, black; rarely chestnut color; nutlets 5, obtuse at the ends, obscurely ridged on the back; stamens 10—20; anthers pale rose color.XIX. Douglasianæ ([page 545]). Fruit subglobose, short-oblong to ovoid, scarlet; nutlets 3—5, acute at the ends, ridged on the back, ventral cavities obscure; leaves scabrate above.XX. Anomalæ ([page 547]).
I. CRUS-GALLI.
CONSPECTUS OF THE ARBORESCENT SPECIES.
Corymbs, leaves, and young branchlets slightly hairy while young, soon becoming glabrous (glabrous while young in 1, 4, 6, 9, and 13). Stamens 10. Anthers rose color or purple. Leaves glabrous, obovate-cuneiform, coriaceous, their veins within the parenchyma; fruit short-oblong to subglobose, dull red often covered with a glaucous bloom.1. [C. Crus-galli] (A). Leaves oblong to ovate, usually acute, coriaceous; fruit short-oblong to subglobose, dark crimson, lustrous, the flesh red and juicy.2. [C. Canbyi] (A). Leaves obovate, usually short-pointed at the broad apex, subcoriaceous; fruit short-oblong to obovoid, bright scarlet.3. [C. peoriensis] (A). Leaves oblong-obovate to oval, or broadly ovate, their petioles glandular with minute stipitate glands; fruit short-oblong to subglobose, orange-red, villose until nearly fully grown.4. [C. fecunda] (A). Anthers yellow. Leaves subcoriaceous. Leaves oval to elliptic, acute or acuminate; fruit short-oblong, green tinged with red.5. [C. regalis] (C). Leaves glabrous, obovate, acute, acuminate, or rounded at apex; fruit short-oblong, dull dark crimson.6. [C. arduennæ] (A). Leaves obovate to oblong-cuneiform, rounded or acute at apex; fruit subglobose to obovoid, dull red, or green flushed with red.7. [C. algens] (A, C). Leaves broadly oval to oblong, rounded or acute or short-pointed at apex; fruit subglobose, dull green tinged with red or cherry-red.8. [C. Palmeri] (C). Leaves thin. Leaves ovate to obovate, acute, dull green above; fruit subglobose, flattened at the ends, dark dull crimson.9. [C. erecta] (A). Leaves oval to oblong-obovate, acute or acuminate, lustrous above; fruit short-oblong, rounded at the ends, bright scarlet.10. [C. acutifolia] (A). Stamens 20. Anthers rose color. Leaves broad-obovate, coarsely serrate; corymbs many-flowered; anthers large, bright rose color; fruit green tinged with dull red.11. [C. Bushii] (C). Leaves narrow-obovate, finely serrate; corymbs few-flowered; anthers small pale rose color; fruit crimson, lustrous.12. [C. Cocksii] (C). Anthers yellow. Leaves oblong-obovate to oblanceolate; calyx-lobes slender, elongated.13. [C. arborea] (C). Leaves oblong-obovate; calyx-lobes short and broad.14. [C. uniqua] (C). Corymbs, leaves, and branchlets more or less villose or pubescent through the season. Stamens 10. Anthers rose color or pink. Leaves finely crenately serrate, scabrate above; anthers rose color.15. [C. Engelmannii] (A). Leaves coarsely serrate with straight teeth, glabrous above; anthers pink.16. [C. montivaga] (C). Anthers yellow (doubtful in 17 and 18). Leaves oval, oblong-obovate or elliptic, acute, thin to subcoriaceous; fruit globose to subglobose, orange-red.17. [C. denaria] (C). Leaves obovate to obovate-cuneiform, rounded or acute at apex, thin; fruit short-oblong, dark red, more or less pruinose.18. [C. signata] (C). Stamens 20. Anthers rose color. Leaves oblong-obovate, acute, scabrate; fruit short-oblong, dull green tinged with red, slightly pruinose.19. [C. edita] (C). Leaves oblong to obovate-cuneiform, rounded and obtuse or occasionally acute at apex, glabrous or scabrate above; fruit globose to subglobose or short-oblong, dark red.20. [C. tersa] (C). Anthers yellow. Leaves oblong-obovate, rounded or gradually narrowed at apex, subcoriaceous, pale below; fruit subglobose, orange color with a red cheek.21. [C. berberifolia] (C). Leaves oblong or obovate-cuneiform, rounded and obtuse or rarely acute at apex, coriaceous, glabrate or slightly scabrate above; fruit subglobose, orange or yellow with a red cheek.22. [C. edura] (C). Leaves oblong to obovate-cuneiform, rounded or acute at apex, subcoriaceous, glabrous or glabrate above, pale below; fruit ellipsoid to short-oblong, yellow.23. [C. crocina] (C). Leaves oblong to obovate-cuneiform, rounded or obtuse or rarely truncate at apex, coriaceous, scabrate above; fruit globose to subglobose, bright red or scarlet.24. [C. fera] (C). Leaves obovate, acute, thin to subcoriaceous; fruit subglobose to short-oblong, somewhat flattened at apex, bright orange-red.25. [C. Mohrii] (C).
1. [Cratægus Crus-galli] L. Cock-spur Thorn.
