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.
Trees or shrubs, erect or decumbent. Leaves alternate, very small and persistent, or larger and deciduous. Flowers in sparse axillary or terminal cymes, or solitary, small, white, with calyx woolly on the outside. Fruit a drupe containing 3 to 5 hard 1-seeded stones. About fifteen species are reported, from Europe, North Africa, Asia, and Mexico. The name is said to be derived from cotoneam, a quince, and aster (ad instar), likeness, from the similarity in structure.
1. C. vulgaris. - A small erect shrub. Leaves small for this section, about 1 to 2 inches long, oblong, ovate or rotun-date, pubescent beneath. Flowers small, pink, in axillary cymes. Berries spherical, shining, scarlet, yellow, or black-A rare native, but common on the Continent.
2. C. affinis. - A small tree with ovate-lanceolate mucro-nulate quite entire leaves about 3 or 4 inches long, glabrous above, hairy beneath. Flowers in large cymes. This and the following are used as stocks for grafting the evergreen sorts upon, but they are none the less devoid of interest in themselves. Nepal.
3. C. frigida. - A more robust growing tree, larger in all its parts. The large clusters of scarlet berries form the chief attraction of these trees. This and the last are considered to be mere forms of 0. bacillaris, a common Indian species.
4. C. Simonsii. - This species is intermediate in character between the deciduous and evergreen. Leaves about an inch long, oval, acute, entire, sparsely clothed with silky hairs, persistent in mild winters. Flowers few together, nearly sessile on short lateral branches. Berries oblong, bright, vermilion coloured, persistent through the Winter. Although deciduous this is one of the most desirable shrubs of this genus.
5. C. microphylla. - Branches thick. Leaves crowded, about 3 or 4 lines long, oblong, obovate or obcordate, dark green and shining above, hairy beneath. Flowers sub-solitary on the short lateral branches. Berries turbinate or spherical, dull red. This is valuable for covering walls, banks, etc. Nepal.
6. C. Wheeleri. - Branches long and slender. Leaves distant, about an inch long, oblong, elliptical or obovate, mucronulate, dark green and shining above, densely hairy below. Berries spherical, dull red. Very pretty as a standard, but it does not appear to produce its fruit so freely as some of the other species.
7. C. buxifolia. - A small shrub near the last with smaller obovate or rotundate leaves. Berries scarlet, obovate or turbinate. Flowers sub-solitary, rather large. Northern India.
8. C. thymifolia. - A prostrate creeping shrub resembling No. 5 in foliage; but the lateral branches are elongated, the leaves narrow, oblong or obovate, not glossy, and of a paler green. This species rarely produces berries on young plants. Northern India.