S46 
ROSACEAE 
cymose infls. of various types, and show a great variety of forms. 
The receptacle is generally hollowed to a greater or less extent, so 
that various degrees of perigyny occur. Frequently there is a central 
protuberance bearing the cpls., even in the forms with very much 
hollowed receptacle. In a few cases (suborders II, IV) the cpls. are- 
united to the receptacle and fully inferior, 
a part of the fruit. The fir. is usually £ 
and actinomorphic. K 5, often with 
an epicalyx of outer and smaller leaves 
(see Potentilla), usually imbricate; C 5, 
usually imbricate; A 2, 3 or 4 times 
as many as petals, or 00 , bent inwards 
in bud ; G usually apocarpous and 
superior, rarely syncarpous or inferior ; 
cpls. as many or 2 or 3 times as many 
as petals or 00 or 1 — 4. Ovules ana- 
tropous, usually 2 in each cpl. Style 
often lateral or basal. Fruit various, 
dry or fleshy ; often an aggregate of 
achenes (Potentilla) or drupes (Rubus), 
or a single drupe (Prunus), or pome 
(Pyrus), and so on (see p. 108 and genera, esp. those mentioned, and 
Fragaria, Geum, Rosa, Poterium). Seed usually exalbuminous. 
The flrs. in general are of simple type, with but slightly concealed 
honey (p. 90) and 00 sta. (p. 123). They are usually protandrous. 
Poterium sp. are anemophilous. 
Few are of economic value (see Pyrus, Rubus, Fragaria, Prunus), 
but many are favourites as garden plants and shrubs. 
Classification and chief genera (after Focke in Nat . PJl., q.v.). 
R. are very closely related to Saxifragaceae, some genera being 
almost arbitrarily placed in one order or the other; they are also 
nearly allied to Calycanthaceae, Combretaceae, Myrtaceae (the floral 
diagram of M. is practically the same as that of suborder II), Thyme- 
laeaceae, and Leguminosae (through suborder VI). 
I. SPIRAEOIDEAE (cpls. 12 — 1, usually 5 — 2, whorled, 
neither on special carpophore nor sunk in receptacle, with 2 
or more ovules in each ; fruit usually dehiscent ; sta. on broad 
base, tapering upwards ; stipules often absent) : 
1 . Spiraeeae (follicle, seeds not winged) : Spiraea. 
2. Quillajeae (follicle, seeds winged): Quillaja. 
3. Holodisceae (achene) : Holodiscus. 
II. POMOIDEAE (cpls. 5 — 2, united to inner wall of receptacle, 
usually syncarpous; axis fleshy in fruit, stipules) : 
4. Pomarieae: Pyrus. 
III. ROSOIDEAE (cpls. 00 or rarely 1 on carpophore, sometimes 
enclosed in axis in fruit; fruit r-seeded indehiscent) : 
The receptacle often forms 
e 
Floral Diagram of Potentilla 
fruiicosa (after Eichler). ep. 
= epicalyx, st. = stipules of 
bracts and bracteoles. 
