This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
The fruit can be sown broadcast in beds without any separation of the seeds, and heavily mulched until the spring of the second year, when the mulching should be removed. This method, however, is not considered good, and has been given up. The best way is to soak the fruits in water, and by maceration the seeds or nutlets are separated from the pulp, and the seeds will sink to the bottom of the tub or vessel. The seeds are then dried in the sun as they can then be handled easily. They are sown in "flats" of convenient size to handle, and piled up in the corner of the shade house and fitted tightly above each other to prevent mice getting at them. During this period of rest they must not be allowed to become dry. In the spring of the second year they are spread out to allow the seeds to germinate. Numbered zinc tags are nailed on the "flats" and the corresponding numbers with the names of the species are recorded.
The American hawthorns can be grafted readily on potted seedling stocks in the greenhouse in winter, any of the species in the Crus-galli group being good to use. They are grafted at the crown. This, however, is an unnecessary operation. All of the species of American hawthorns (and there are over 900 of them) come absolutely true from seed, and whilst they germinate slowly, they start to grow rapidly into plants of good stocky size from about two years after they germinate.
Some of the species of American hawthorns have highly colored foliage in the fall. The species in the Pruinosae, Medioximae and Intricatae groups have perhaps the most highly colored foliage. Notable examples are Crataegus opulens, C. diffusa, C. maineana, C. dis-sona, C. cognala, C. conspecta, C. promissa, C. exornata, C.perjucunda, C. foetida, and C. verecunda.
The different species vary greatly in the time of ripening their fruits and in the period of duration. In many instances the fruit drops soon after ripening and in others hangs on for a long period. A selection of twenty-six species that would give a good fruit display from August until early or mid-winter, would be as follows: Crataegus matura, C. praecox, C. Arnoldiana, C. Dayana, C. Robesoniana, C. pedicellata, C. gloriosa, C. Ellwangeriana, C. lauta, C. svhmollis, C. champlainen-sis, C. arkansana, C. Dunbari, C. ferentaria, C. opulens, C. compta, C. gemmosa, C. livoniana, C. geneseensis, C. persimilis, C. maineana, C. Barryana, C. coccznioides, C. leiophylla, C. durobrivensis, and C. cordata. (See pp. 887-889 for some of these.) John Dunbar.
A. Veins of the Ivs. extending to the points of the lobes or to the teeth only; Ivs. usually slightly or not lobed: fruit not black or blue, except in No. 37. b. Stones plain on the inner surfaces. c. Petioles elongated, usually slender. d. The petioles glandular at the apex or sparingly glandular throughout. E. Corymbs many-fid.: petioles glandular only at the apex: Ivs. broad at the base, truncate to broadly cuneate. p. Leaves tomentose or pubescent beneath, at least on the veins. G. Stamens 20; anthers pale yellow: leaves thick and leathery. H. fruit ripening in Aug. and Sept.: leaves broadly ovate. .......... 1. mollis
HH. fruit ripening at the end of Oct.: leaves oblong-ovate to oval.........2. arkansana
GG. Stamens 10: leaves membranous at maturity. H. Anthers yellow.
I. fruit crimson, villous, ripening the middle of Aug.: leaves dark green and smooth above...... 3. Arnoldiana
II. fruit orange-red, lustrous, puberulous at the base: leaves dark yellowish green, scabrate above .... 4. submollis hh. Anthers rose-color: leaves scabrate above. l. Plant a tree: leaves with short lobes: corymbs many-fid......... 5. Ellwangeriana ii. Plant a shrub: leaves rather deeply lobed: corymbs 4-6-flowered. . 6. Robesoniana ff. Leaves glabrous beneath or nearly so. g. fruit bloomy until nearly fully ripe. h. Stamens 20: leaves glabrous: fruit subglobose, often 5-angled....... 7. pruinosa hh. Stamens 10: leaves scabrate above, while young: fruit obovoid ... 8. Barryana GG. fruit not bloomy.
h. Stamens 20, anthers pink: leaves truncate at the base.
I. The leaves dull above, villous beneath when young: fruit
with conspicuous calyx and with red flesh............. 9. coccinioides
II. The leaves lustrous above, quite glabrous: fruit with yellow flesh and small calyx.. . 10. speciosa hh. Stamens 5-10: leaves broadly cuneate. I. Anthers pink or rose-purple; stamens usually 10. 3. Calyx-lobes coarsely glandular-serrate: stones usually 5: leaves distinctly lobed. .11. pedicellata jj. Calyx-lobes entire or obscurely serrate: stones 2-8: leaves slightly lobed...........12. pastorum
II. Anthers yellow; stamens 5-10: leaves orbicular-ovate: fruit
with 2-3 stones......13. rotundifolia ee. Corymbs usually few-fid.: petioles sparingly glandular throughout: leaves cuneate at the base: stamens 10.
F. Calyx-lobes glandular-ciliate: corymbs slightly villous: anthers yellow..........14. intricata
FF. Calyx-lobes entire or glandular above the middle: corymbs glabrous. G. Anthers purplish: calyx-lobes glandular above the middle...............15. Buckleyi gg. Anthers yellow: calyx-lobes without glands.....16. Boyntonii dd. The petioles glandless or with a few minute glands: leaves cuneate at the base, ovate to lanceolate, not or very slightly lobed, lustrous above, glabrous at maturity: stamens 20. e. fruit subglobose, 1/4in. across or less, bright scarlet or orange: leaves oblong-obovate to ovate. . . 17. viridis ee. fruit ovoid, about 1/2in. across, dull brick-red, bloomy: leaves lanceolate to oblong-obovate. 18. nitida cc. Petioles short; leaves cuneate at the base, not or very slightly lobed. d. The petioles glandless. e. Corymbs many-fid.