DICOTYLEDONES— CALYCIFLOR.E 333 



or odd petal with its margins inside the lateral petals. Illus- 

 trative Genera : — C8esalpinia,Z/i/?n. ; Cassia, Linn. There are 

 no British plants in this siib -order. 

 Sub-order 3. Mimose.e. — Petals equal, valvate in aestivation. 

 Stamens often oo . Pollen slightly coherent. Leaves some- 

 times replaced by phyllodes. Illustrative Gener-a : — Mimosa, 

 Linn. ; Acacia, Willd. There are no British plants in this 

 sub -order. 



Distribution and Numbers. — This is a very extensive order, 

 and has some representatives in almost every part of the world. 

 A considerable number of the genera are, however, confined 

 within certain geographical limits, while others have a very wide 

 range. As a general rule, the Pajyilionacece are universally dis- 

 tributed, although most abundant in warm regions ; while the 

 CcBsal^piniece Sin([Mi})Wsece are most commonin the tropics; but 

 many of the latter are also to be found in Australia. There are 

 about 7,000 species in this order. 



ProjJerties and Uses. — The properties and uses of the plants 

 of this order are exceedingly variable. Many are valuable fodder 

 plants, others yield timber, gums, drugs, and dyes. Some species 

 are poisonous. 



Order 121. Rosacea, the Rose Order. — Character. — Ti-ees, 

 sliruhs, or lierhs. Leaves simple or compound, alternate, usually 

 stipulate. Floiuers regular, generally hermaphrodite, or rarely 

 unisexual. Thalamus more or less convex, elongated, or con- 

 cave, or tubular ; the tube sometimes becoming fleshy as the 

 fruit develops, and often so enclosing the carpels as to make the 

 fruit spuriously syncarpous and inferior. Calyx gamosepalous, 

 sometimes partly adherent to the tube of the thalamus ; 4- or 5- 

 lobed ; when 5, the odd lobe posterior ; sometimes surrounded 

 by a whorl of bracts forming an involucre or epicalyx. These 

 are by some botanists considered to represent stipules of the 

 sepals. Petals 5, distinct, perigynous ; or rarely none. Sta- 

 mens definite or x , perigynous. Carpels 1, 2, 5, or numerous, 

 with 1-celled ovaries ; usually apocarpous and superior; some- 

 times becoming spuriously syncarpous and inferior during the 

 development of the fruit, as in the Pomece ; styles basilar, lateral, 

 or terminal ; ovules 1 or few. Fruit various : either a drupe, an 

 achaenium, a follicle, a dry or succulent etaerio, a cynarrhodon, 

 or a pome. Seeds 1 or few, exalbuminous ; embryo straight. 



Diagnosis. — Trees, shrubs, or herbs, with alternate leaves. 

 Flowers regular. Calyx 4 — 5-lobed ; when 5, the odd lobe pos- 



