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THE NEW STUDENT'S REFERENCE WORK

b. The  dispersal   of   seeds

1717.

(1)  By currents  of  air:    as  the thistle 1904;

milkweed 1226;  dandelion 500;

(2)  By currents of water:   from headwaters to

floodplains and banks.

(3)  By animals:   indigestible seeds;  and grap-

pling appendages.

(4)  By  explosive  fruits:    forcibly  discharging

seeds.

5. THE SHOOT: part of the plant growing upward 1747. a. The Stem:  axis of the plant 1821.

(1) The meristem:   formative  tissue  in all growing organs  1207.

(a) The epidermis:    protective cover-

ing of all higher plants 621;

(b) The   hypodermis:    cells   just   be-

neath epidermis 907;

(c) The collenchyma: having a pearly-

white luster 425.

(d) The hair: cells formed outside the

epidermis 825.

(3) The  periblem:    the  embryonic region  producing cortex  1452.

(a) The cortex: tissue containing the active cells 462; the bark 172; the bast 179; the cork 456.

(4) The plerome:   the embryonic region producing the stele 1504.

[" 1. The vascular bundles: the conducting system 2004; sclerenchyma 1707; the xylem or wood 2118, containing the trachea 1930; the phloem or bast—for the transfer of food 1472.

2. The  heartwood:    the colored wood

854.

3. The   sapwood:   new  wood  through

which sap flows 1678.

(2) The dermatogen:  the

embryonic region producing epidermis 522;

(a) The  stele:    the

central region of mature stems 1821.

(5) The bud:  an undeveloped shoot 283;

" a. Leaf-buds:  from   which    the    axis

grows.

b. Flower-buds: from which the flower comes.

(6)  Rootstock  or rhizom:   an underground  stem 1633.

a. The Tuber:  one form of underground stem 1948; as potato 1537.

(7) The  node:   joints in the stem 1354.

(8) The internodes:   portions of stem between the nodes 933.

b. The Branch:   a repetition of the axis of stem 259.

(1)  Dichotomous branching:   axis dividing into two branches 529.

(2)  Monopodial branching:   giving of branches from side of stem

259.

(3) Chladophyll:    branches  which  replace  leaves   403.

(4) The axil:   where branches normally arise 149.

c. The Leaf:   expanded organ of higher plants, for displaying green tissue to

air and sunlight 1041. (1) Deciduous leaves: growing off every year 512.

2269