536 BOTANY. 



Order Bruniaceee. — A few heatli-like woody plants of South Africa. 



Order Hamamelaceee. — A small order of trees and shrubs, repre- 

 sented in the United States principally by the Witch Hazel {Hama- 

 melis Virginiea); and the Sweet Gum Tree (Liquidamber Styraciflua). 



Order Droseracese. — The Sundew Family. Mostly bog-herbs with 

 radical gland-bearing leaves. About IIQ species are known, distributed 

 throughout the world. This interesting little family has attracted 

 great attention on account of the insect-catching habits of its species. 



The most remarkable plant of the order is the Venus' Fly-Trap {Dioucea 

 muscipula) of North Carolina. Each leaf has a rounded blade which 

 is fringed with stiff bristles (Fig. 469), and upon the surface of each half 

 are three sensitive hairs which, when touched, cause the tissues of tlie 

 upper surface of the midrib to contract suddenly, and thus to quickly 

 close the leaf as a book or rat-trap is closed. An insect alighting upon, 

 one of these leaves is caughtby the quickly-closing sides, and is within 

 a few days dissolved (digested) by an acidulous fluid exuded by the- 

 glands of the leaf ; it is then absorbed by the leaf, and when this is ac- 

 complished the latter again opens. This plant is thus a partial sapro- 

 phyte ! 



In the Sundews (species of Drosera), the leaves have stalked 

 glands which are sensitive, and when these come in contact with an 

 insect they cause the blade to slowly bend around it, finally enclosing^ 

 it. Digestion and absorption then take place as in the previous case. 



Mr. Darwin has shown that the other genera of the order are also in- 

 SRctivorous. (See his book, "Insectivorous Plants," London and New 

 York, 1875, in which 367 pages are devoted to the plants of this order). 



Order Crassulacese. — Herbs or undershrubs, usually with thick 

 fleshy leaves. Species 400, found mostly in temperate climates. Many- 

 are in common cultivation — e.g., Bryophyllum, the Live-leaf from 

 tropical Africa ; Crassula, of many species, from the Cape of Good 

 Hope ; Cotyledon, of many species, from Mexico and Africa ; Sedum-y 

 Live-forever ; Sempervivum, tjie Houseleek, etc. 



Order Saxifragacese. — The Saxifrage Family. Trees, shrubs, and 

 herbs with actinomorphic flowers, generally definite stamens, and 

 seeds rich in endosperm. Species 540, mostly natives of temperate and 

 cold climates. 



Sibes grossularia, the Gooseberry, and R. rubrum, the Red Currant, 

 both of Europe, are in common cultivation for their edible berries. 

 The last named is also indigenous northward in this country. 



Among ornamental plants are PIdladelphus, the Mock Orange, from 

 the Old World ; Mibea, Flowering Currants, of the Western United 

 States ; Deutzia, from China and Japan ; Hydrangea, Japanese and 

 native; Astilbe, from Japan ; Saxifraga swrmentosa, the so-called Straw- 

 berry Geranium, a fine basket plant from China. 



Cephalotus follicularis, the Australian Pitcher Plant, is now regarded 



