Rosaceae-Rose family

110 genera, 3,100 species Widespread but best represented in the Northern Hemisphere, mainly in the temperate and arctic climate.

Salient features:

Herbs shrubs or trees’ leaves are usually serrate, stipules conspicuous, flowers actinomorphic, usually perigynous and numerous, carpel is single or numerous and free, rarely united, and fruit is usually fleshy.

Major genera:

Rubus (750 species), Potentilla (500), Prunus (430), Crataegus (240), Cotoneaster (230), Sorbus (230), Rosa (225), Alchemilla (220), Spiraea (100), Pyrus (60), Malus (55) Geum (40) and Fragaria (15).

Description:

Herbs (Alchemilla, Fragaria), shrubs (Rosa, Rubus) or trees (Prunus, Malus, Pyrus), rarely climbing (some species of Rosa), sometimes with runners (Fragaria), often with prickles and thorns, without latex, nodes trilacunar, rarely unilacunar.

Leaves 

Leaves alternate, rarely opposite (Rhodotypos), simple (Malus, Prunus), palmately compound (Fragaria) or pinnate compound (Sorbaria), leaf blade often with gland-tipped teeth, usually serrate, venation pinnate or palmate, reticulate, stipules present, often adnate to petiole.

Inflorescence

Inflorescence with solitary flowers (some species of Rosa), racemes (Padus), panicles or cymose umbels (Spiraea), sometimes corymbs (Crataegus), rarely catkin-like (Poterium).

Flowers

Flowers bisexual, rarely unisexual (Poterium; plants monoecious or dioecious), actinomorphic, rarely zygomorphic (Parinarium), usually perigynous with distinct hypanthium (flat, cup-shaped or cylindrical); hypanthium free from or adnate to carpels, often enlarging in fruit, with nectar ring on the inside, rarely epigynous (Malus).

Calyx

The calyx is usually with 5 sepals, united at base, sometimes with 3-5 epicalyx (Fragaria) on the outside, often persistent.

Corolla

Corolla usually with 5 petals, free, often clawed, and imbricated.

Androecium

Androecium with numerous stamens, free, 4 in Sanguisorba, 2 in Parastemon urophylla, anthers bithecous, rarely monothecous (Alchemilla), dehiscence longitudinal, pollen grains tricolporate.

Gynoecium 

Gynoecium with 1 (Prunus), 2-3 (Crataegus) to many carpels (Rosa), usually free, rarely connate (Crataegus, Pyrus), sometimes adnate to hypanthium, ovary superior or inferior, usually unilocular, ovules 1,2 or more, unitegmic or bitegmic, crassinucellate, placentation basal, lateral or apical, rarely
axile (Pyrus).

Fruit

Fruit a follicle (Spiraea), achene (Rosa), a drupe (Prunus), pome (Malus), or aggregate (etaerio of achenes in Potentilla, etaerio of drupes in Rubus); seed with the straight embryo, without endosperm. Pollination mainly by insects. Dispersal by birds, animals, or wind.

Economic importance:

The family is largely known for its temperate fruits: apple (Malus Domestica), pear (Pyrus), plums (Prunus- several species), cherries (Prunus avium, P. cerasus) peaches (Prunus persica), almonds (Prunus dulcis), apricots (Prunus armeniaca), strawberry (Fragaria vesca), loquots (Eriobotrya), raspberries (Rubus), quince (Cydonia), etc.

Popular ornamentals include species of Rosa, (rose) Rubus (raspberry), Chaenomeles (flowering quince), Potentilla (cinquefoil), Geum (avens), Cotoneaster, Crataegus (hawthorn), Pyracantha (firethorn), and Sorbus (mountain ash). Flowers of Rosa damascena are used for extracting attar of
roses.

The bark of Quillaja (soap-bark tree) contains saponin used as a substitute for soap in cleaning textiles, and also yields tannin. The bark of the Moquilla utilise (pottery tree) of Amazon is used in making heat-resistant pots. The wood of Prunus serotina is used for making furniture and cabinets. Several species are also valuable sources of timber.