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THE STRUCTURE OF PLANTS. 3 
pit s having embryos of this kind are termed Di wcotyledonous (. ¢. 
aving two cotyledons or seed-leaves). There are many plants in which 
the embryo has but one cotyledon ; this is the case with Wheat, 
(Fig. 238). 
extended surface by being ceneral ‘abide ae branches ey ed 
plied with multitudes of delica mg ee e root of a 
plant, which spri ings from the pee ree ite pana ca produces 
flowers and seed all in one year, is called @ dhssastel When the plant re- 
ipongh a number of years, it is perenni 2 
10. The various forms which roots s present, produced either by the ae 
branching of the principal root, or a) Be ealangemen nt of it and that of its g 
ranches, ere the main root continues distinct and unbranching, or 
sends off only occasional branches, a ass is il ordinarily, how- 
ever, the main root is lost in its numerous branches, or many roots 
start from the lower end of the radicle, and we have a cluster of roots. 
Annual roots are re very much divided into numerous thread-like branches ; 
a int termed Pgh roots. In biennial plants, the first year is occu- 
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seunple), we have a sede segs’ or fusiform eae hen much en- 
laterally, so as to be than I 
la so r an long, the haped 
or napiform. In these Sie hac branches are small sabe pe Pate te 
some perennial roots, those where the stem dies down annually, there is 
oe pres, ee of nourishment oat the roots become fberonit 
in ‘ 
os a Under fevers circumstances, roo 
tion of the stem and branches. 
ts), wehich sense 1 fom ae 
lants, adherin De 
ain the Ivy and Polson Oak 
: plant, as 
