General description:- Trees, shrubs or herbs.
Leaves:- Usually alternate and stipulate.
Flowers:- Regular, usually hermaphrodite, the sepals, petals and stamens are carried up around the ovary on a hypanthium (perigynous) or the sepals, petals and stamens (are apparently inserted higher than the ovary) (epigynous). Hypanthium flat, concave or tubular. Sepals usually 5, sometimes with epicalyx. Petals usually 5, free, sometimes absent. Stamens usually 2, 3 or 4 times as many as the sepals, sometimes 1-5 or indefinite. Carpels 1 to numerous, free or joined margin to margin (connate), sometimes attached to the surface (adnate) of the hypanthium. Ovules usually 2, sometimes 1 or more, bent parallel to its stalk (anatropous). Styles free, rarely united.
Fruit:- Of one or more achenes, drupes or follicles, or a pome, the hypanthium sometimes becoming coloured and fleshy. Endosperm usually absent.
The term 'hypanthium' is used to denote that part of the flower which bears the sepals, petals and stamens on its outer or upper margins, and on which the carpels are borne. The hypanthium is often, at least in part, receptacular in nature, but it is sometimes fused, to a variable extent, with the walls of the carpels, the exact line of demarcation being difficult to determine.
AMELANCHIER
General description:- Deciduous shrubs or small trees, without spines.
Leaves:- Simple, serrate. Stipules caducous.
Flowers:- In terminal racemes, rarely solitary. Petals linear to oblong-obovate, not clawed, white, rarely pink; stamens 10-20; carpels 5, connate or partly free, with walls cartilaginous in fruit; ovules 2; styles 2-5, free or united (connate) at the base.
Fruit:- Small, 4- to 10-celled, bluish- or purplish-black, usually juicy and sweet.
1) Flowers in umbels, racemes or few-flowered clusters.
2) Petals linear to oblong-ovate, not clawed.
APHANES
General description:- Deciduous shrubs or small trees, without spines.
Leaves:- Deeply dissected and conspicuous, connate stipules.
Flowers:- In condensed, leaf-opposed cymes; stamen 1(rarely 2), inserted on inner margin of disc.
1) Petals 0.
2) Leaves simple or digitately divided.
3) Annual stamens 1(-2).
COTONEASTER
General description:- Shrubs, rarely small trees, without spines.
Leaves:- Entire. Stipules caducous.
Flowers:- Small, in cymes or corymbs, or solitary. Sepals persistent; petals white or pink; stamens c. 20; carpels 2-5, free on the ventral side, with walls stony in fruit; ovules 2; styles 2-5, free.
Fruit:- Red or black, with mealy flesh; pyrenes 2-5.
Key features:-
1) Carpels enclosed in and adnate to the hypanthium.
2) Fruit a pome, red or black.
3) Flowers solitary, less than 1 cm diam, in 2- to many-flowered inflorescences.
4) Walls of carpels becoming stony in fruit.
5) Leaves entire.
CRATAEGUS
General description:- Deciduous, usually spiny shrubs or small trees.
Leaves:- Simple, lobed or pinnatifid, serrate. Stipules persistent.
Flowers:- In corymbs. Petals obovate, white, rarely pink; stamens 5-25; carpels 1-5, free on the ventral side, walls stony in fruit; styles 1-5; ovules 2.
Fruit:- Red, yellow or black, usually with mealy flesh; pyrenes 1-5.
Key features:-
1) Stipules persistent.
POTENTILLA
General description:- Perennial, rarely annual or biennial herbs, or small shrubs.
Leaves:- Digitate, pinnate or ternate.
Descriptions of leaves and leaflets refer only to the basal and lower cauline leaves.
Flowers:- Solitary or in cymes, (4-)5(-6)-merous. Hypanthium more or less flat, with a central, hemispherical, dry or spongy receptacle; epicalyx present; stamens 10-30; carpels (4-)10-80; style nearly basal, lateral or terminal. Styles usually not persistent.
Fruit:- A head of achenes.
Key features:-
1) Styles short, deciduous.
2) Leaves ternate, digitate or digitately lobed.
3) Receptacle swollen, and fleshy or spongy in fruit.
4) Petals purple, more than 2 mm.
5) Stamens 10 or more.
7) Carpels 2-6.
8) Flowers 4-merous.
9) Carpels more than 5, developing into achenes.
PRUNUS
General description:- Shrubs or trees.
Leaves:- Simple, usually with rounded to saw-toothed margins (crenate or serrate), stalked (petiolate). Stipules free, narrow, more or less thin and dry (scarious), often deciduous.
Flowers:- 5-merous, solitary or in clusters, umbels, corymbs or racemes. Petals pink or white.
Key features:-
1) Stipules falling eary (caducous).
2) Carpels 1, connate at base.
3) Leaves not lobed.
4) Fruit a drupe.
ROSA
General description:- Shrubs, usually deciduous.
Stems:- Usually with prickles.
Leaves:- Composed of more than three leaflets (pinnate); stipules usually attached to (adnate) to the petiole.
Flowers:- Terminal, solitary or in corymbs, (4-)5-merous. Hypanthium urceolate, becoming coloured and fleshy in fruit; epicalyx absent; stamens and carpels numerous; styles protruding through the orifice of a disc, sometimes forming a short column; ovules 1.
Fruit:- A pseudocarp of numerous achenes enclosed in the hypanthium.
Most species occur in scrub, woodland and hedges.
The description of leaves always refers to the best-developed leaves on the flowering stems.
Key features:-
1) Carpels enclosed in the hypanthium.
2) Usually spiny shrubs.
3) Carpels numerous, free.
Sect. CANINAE
General description:- Deciduous shrubs, with erect or arching stems.
R. CANINA Group
Stems:- Up to 5 m, erect.
Prickles:- Usually curved or hooked, stout, usually all similar.
Leaves:- Leaflets ovate, obovate, elliptical or suborbicular, glabrous or pubescent, eglandular or with a few glands on the main veins beneath, more rarely with numerous glands, the glands not strongly scented.
Flowers:- Pedicels glabrous or stipitate-glandular. Flowers solitary or 2-5. Sepals 3-5 mm wide, usually deflexed after anthesis but sometimes erect or spreading (patent). Petals white or pink. Disc flat. Styles short or long, glabrous, villous or lanate.
Fruit:- Globose, ovoid or ellipsoid, glabrous or stipitate-glandular.
1) Sepals 3-5 mm wide, deflexed and deciduous after anthesis.
2) Prickles stout, curved or hooked, usually with stout bases.
3) Leaflets green.
4) Young stems not pruinose.
5) Pedicels glabrous.
5) Leaflets not coriaceous, usually not scented.
6) Leaflets glabrous or pubescent, very rarely tomentose and if tomentose then prickles distinctly curved or hooked and hypanthium glabrous.
R. RUBIGINOSA Group
General description:- Erect shrubs
Stems:- Up to 3·5 m.
Prickles:- Usually hooked or curved, sometimes mixed with acicles and glandular setae.
Leaves:- Leaflets Suborbicular, ovate, obovate or elliptical, rounded or cuneate at base, biserrate to compound serrate, glabrous or somewhat pubescent, never tomentose, more or less densely glandular-viscid beneath, smelling of apples; teeth glandular. Pedicels glabrous or glandular-hispid.
Flowers:- Solitary or 2-3. Sepals pinnatifid, erect or deflexed after anthesis. Petals small, white or pink. Styles short or long, glabrous, villous or lanate.
Fruit:- Globose, ovoid or ellipsoid, glabrous or glandular-hispid.
Key features:-
1) Leaflets not coriaceous, ± densely viscid-glandular beneath.
2) Petals 8-25(-30) mm.
3) Leaflets glabrous or somewhat pubescent beneath, smelling of apples.