This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Deciduous trees or shrubs, often armed with sharp spines. Leaves variable. Calyx-limb persistent. Fruit ovoid or spherical, with hard bony cells or stones. The species are numerous, and distributed throughout the northern temperate zone. The name is from Kpatos, strength, referring to the durable wood.
1. C. Oxyacantha, including (7. monogyna (fig. 95). Whitethorn, Hawthorn, May, or Quick.- A common native bush or small tree extensively employed for hedges. In a wild state the flowers of this species vary from pure white to pink, and the foliage in size and beauty; but under cultivation it has produced many exceedingly handsome varieties far superior to the ordinary forms. These varieties include double white, pink, and scarlet flowers, with correspondingly larger and bolder foliage, and also variegated and weeping forms.
Fig. 95. Crataegus Oxyacantha. (1/4 nat. size.)
2. C. Pyracantha. - A very distinct species with small persistent lanceolate or oblong acute serrate leaves and pinkish or white flowers succeeded by dense clusters of orange-scarlet berries, which hang during the greater part of the Winter. This species is very commonly used and very suitable for covering walls. A variety exists with white berries. A native of the South of Europe.
3. C. coccinea. - A handsome shrub or small tree with a few straight thorns or unarmed, large ovate-cordate or oblong angularly lobed and toothed glabrous leaves on rather long petioles. Flowers large, in lateral corymbs, white; anthers red. Fruits large, bright red, very effective in Autumn. A native of North America.
4. C. Crus-gdlli. Cockspur Thorn.- A small shrub or tree beset with strong curved spines. Leaves glabrous and glossy above, lanceolate or. oblong-cuneate, narrowed into a short petiole, serrulate or irregularly lobed. Flowers large, white. Fruits bright red and showy. There are several varieties, such as ovalifolia, pyracanthifolia, etc. It is also known under the names lucida and laurifolia.
C. pyrifolia and C. prunifolia are varieties of an allied North American species, C. tomentosa: the former has very large oblong irregularly toothed leaves, large corymbs of white flowers, and orange pear-shaped medium-sized fruits; and the latter has smaller scarlet fruits, though otherwise very much like the Cockspur Thorn, except in the pubescence of some parts. C. Dougldsii is another of the same group with reddish twigs and oval or roundish cut and serrated glabrous leaves. C. Mexicana is an American species, rarer in cultivation, and certainly not so ornamental as some of the above. C. Azarolus is a South European species, in the way of the common Hawthorn, with thicker leaves having broader woolly segments, and larger yellow or pale red berries.