SAXIFRAGALS. 459 
These orders consist of evergreen shrubs, trees, and herbaceous 
plants, which are, with few exceptions, confined to the tropics of 
both hemispheres and the warmer parts of Europe. The excep- 
tions are the U_mace#, or Elms, which have usually been classed 
among the Urticacesé, from which Mirbel has separated them, 
in which he has been followed by Dr. Lindley. They differ from 
Urticacee in having a two-celled fruit and hermaphrodite flowers. 
The Elm (Ulmas campestris) (Pate XVII.) is generally found in 
mountain woods, and it is not uncommon to find it planted by 
_ road-sides and in places of public resort. It is a large tree, with 
branchless stem; a cone-shaped head, formed of strong ascending 
branches, abundantly farnished with close, compact, and regularly 
distichous boughs. Its leaves are alternate, furnished with two 
caducous stipules, oval, acute, and irregularly oblique at the base ; 
doubly dentate, and generally pubescent and rough. They only 
appear after the flowers, which are reddish, and arranged in sessile 
fascicles, or bundles. Each flower, always without 
corolla, consisting of a calyx of four or five lobes, 
with four to five stamens opposite to these lobes, 
having bilocular anthers, opening from without by 
five longitudinal clefts; a free, two-celled ovary, 
containing a single anatropal ovoid. The fruit, or 
samara, of the Elm (Fig. 422) is dry, compressed, 
largely winged, membranous in all its circumference, ae 
hollow at the summit, indchiscent, and unilocular. — Samara of the Elm. 
The various species of Elm are found wild in most parts of the 
world. They are trees or shrubs of the North of Asia, of the 
Mountains of India, of North America, China, and Europe. There 
is a peculiarity belonging to the seeds of the Elm; they do not 
produce trees precisely like the parent tree, the difference being 
so considerable as to have led, as most botanists think, to the 
multiplication of species in cases where this variation alone caused 
the difference. This very peculiarity, however, renders the Elm 
_ & favourite object in ornamental planting. The Common Elm is | 
_ Tepresented in Plate XVII. oe 
The Rhamnacee, Sapotacee, and Styracacee, belonging to this 
group, produce med'cinal plants of considerable importance. The 
tries of various species of Rhamnus are violent purgatives ; some 
