File:Foundations of botany (1901) (14597491548).jpg

Identifier: foundationsofbot00berg (find matches)
Title: Foundations of botany
Year: 1901 (1900s)
Authors: Bergen, Joseph Y. (Joseph Young), 1851-1917 Bergen, Joseph Y. (Joseph Young), 1851-1917. Bergen's Botany: key and flora, Northern and Central States ed. 1901
Subjects: Plants
Publisher: Boston : Ginn
Contributing Library: The LuEsther T Mertz Library, the New York Botanical Garden
Digitizing Sponsor: The LuEsther T Mertz Library, the New York Botanical Garden

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
Fig. 109. —Opposite Leaves of Deutzia^ (from the same shrub as Fig. 110), asarranged on a Horizontal Branch. ■ 150. Leaf-Mosaics. — In very many cases the leaves atthe end of a shoot are so arranged as to form a prettysymmetrical pattern, as in the horse-chestnut (Fig. 107).When this is sufficiently regular, usually with the spacebetween the leaves a good deal smaller than the areas ofthe leaves themselves, it is called a leaf-mosaic (Fig. 111).Many of the most interesting leaf-groups of this sort (as 1 Deutzia crenata. LEAF EXPOSURE TO SUN AIST) AIR 143
Text Appearing After Image:
Fig. 110. — Opposite Leaves of Deutzia, asarranged on a Vertical Branch. in the figure above mentioned) are found in the so-calledroot-leaves of plants. Good examples of these are the dandelion, chicory, falldandelion, thistle, hawk-weed, pyrola, plantain.How are the leaves ofthese plants kept fromshading each other? 151. Much-DividedLeaves. — Not infre-quently leaves are cutinto slender fringe - likedivisions, as in the carrot,tansy, southernwood,wormwood, yarrow, dog-fennel, cypress-vine, and many other common plants. Thiskind of leaf seems to be adapted to offer considerablesurface to the sun without cut-ting off too much light fromother leaves underneath. Sucha leaf is in much less danger ofbeing torn by severe winds thanare broader ones with undividedmargins. The same purposesare served by compound leaveswith very many small leaflets,such as those of the honey-locust, mimosa acacia (Fig. 113),and other trees and shrubs of the pea family. What kindof shade is produced by a hor

Note About Images