ROSACEA. 541 
638), or terminal (fig. 949); ovules 1 (fig. 955) or few (fig. 950). 
Fruit various: either a drupe (jigs. 698—695), an achenium, a 
follicle, a dry or succulent etzerio (figs. 661 and 703), a cynar- 
rhodum, or a pome (jigs. 473 and 722). Seeds 1 (figs. 953 and 
954) or few (fig. 473), exalbuminous ; embryo straight. 
Diagnosis.—Trees, shrubs, or herbs, with alternate leaves. 
Flowers regular. Calyx 4—5-lobed; when 5, the odd lobe pos- 
terior. Petals 5, perigynous, orrarelynone. Stamens perigynous, 
distinct ; anthers 2-celled. Carpels one or more, usually distinct 
or sometimes united; generally superior or occasionally more or 
less inferior. Seeds 1 or few, exalbuminous; embryo straight. 
Division of the Order and Illustrative Genera.—The order 
Rosacez, as above defined, may be divided into five sub-orders, 
which are by some botanists considered as distinct orders. 
They are characterised as follows :— 
Sub-order 1. CuHrysoBALANE®.—Trees or shrubs, with simple 
leaves and free stipules. Carpel solitary, cohering more or 
less on one side with the tube of the calyx; ovules 2; style 
basilar. Fruit adrupe. Seed erect ; radicle inferior. Illustra- 
tive Genus:—Chrysobalanus, Linn. There are no British 
plants in this sub-order. 
Sub-order 2. Drupacea.—Trees or shrubs, with simple leaves 
and free stipules. Calyx deciduous. Carpel solitary, not ad- 
herent to the calyx; style terminal. Fruit a drupe. Seed 
suspended (jig. 953). Illustrative Genus :—Prunus, Linn. 
Sub-order3. Rost&.—Shrubs or herbs, with simple or compound 
leaves and adherent stipules. Carpels 1 or more, superior, 
not united to the flower-tube, distinct or sometimes more or 
less coherent; styles lateral or nearly terminal. Fruit either 
an etzrio, cynarrhodum, or consisting of several follicles. 
Seed usually suspended ( fig. 955), or rarely ascending ; radicle 
superior. Illustrative Genera :—Rosa, Linn. ; Rubus, Linn. 
Sub-order 4. SancuisorBE® or Porertex.—Herbs or under- 
shrubs. Flowers often unisexual. Petals frequently absent. 
Carpels 1—3; style terminal or basilar (fig. 952). Fruit an 
achznium enclosed in the flower-tube, which is often in- 
durated. Seed solitary, suspended, erect, or ascending. 
Illustrative Genera :—Alchemilla, Linn. ; Poterium, Linn. 
Sub-order 5. Pomex.—Trees or shrubs, with simple or compound 
leaves and free stipules. Carpels 1 to 5, adhering more or 
less to each other and to the sides of the flower-tube, and 
thus becoming inferior; styles terminal (fig. 950). Fruit a 
pome, 1—5-celled or rarely spuriously 10-celled (figs. 473 and 
722). Seeds erect or ascending. Illustrative Genera :—Pyrus, 
Linn. ; Crategus, Linn. 
Distribution and Numbers.—The Chrysobalanex are princi- 
pally natives of the tropical parts of America and Africa. The 
Drupacex are almost exclusively found in the cold and tem- 
