142 FAMILIES OF FLOWERING PLANTS 
The most important genus is Geranium, represented in this coun- 
try and in the Old World by numerous species, whose flowers range in 
size from those of the Carolina cranesbill (G. Carolinianum) and the 
herb Robert (G. Robertianum), to the large-flowered Alaskan species 
shown in Fig. 123. The cultivated geraniums belong mostly in the 
genus Pelargonium, distinguished by the somewhat irregular corolla. 
They have been wonderfully developed by long cultivation and hybrid- 
ization. The genus LErodium, 
widely distributed in temperate 
regions of the Old World, is rep- 
resented by three native species 
on the Pacific coast which fre- 
quently become bad weeds. 
They are known by the Spanish 
name of “alfilerilla.”’ 
Family Oxalidaceae. Oxalis 
Family. Contains about 7 gen- 
era and 270 species, 250 of which 
are comprised in the single genus 
able habit, or in a few instances 
shrubs. There is remarkable di- 
versity in the leaves; while usu- 
ally palmately 3-foliolate they 
are sometimes pinnate or even 
undivided and peltate (shield- 
shaped). The various shapes 
are shown in the four species of 
Oxalis represented in Fig. 124. 
The flowers are solitary or more 
often in forking cymes; sepals 
and petals 5, stamens 10-15; 
Fig. 124. Species of Oxalis or sorrel. 1. O. versi- OVAYY 5-celled, usually capsular 
sicolor. 2. O. commutaia, 3 0. approximata, 49. in fruit. The juice of the plants 
hirta, Allone-half natural size. Original. a ies 
contains a sour principle due to 
oxalic acid. The various wild species of Oxalis are known as wood- 
sorrels; they have white, yellow or purple flowers. South Africa, par- 
ticularly the Cape region, is the metropolis for these plants, and many 
varieties now in cultivation have come from there. 
Family Tropaeolaceae. Tropaeolum Family. Consists of a single 
genus, Tropaeolum, including about 35 species, natives of the higher 
parts of Central and South America. They are herbs, erect or climb- 
ing by means of twisting leaf-stalks. The leaves are simple, and pel- 
Oxalis. They are herbs of vari- 
