22 THE FLOWERING PLANT. 
members, leaves, which usually differ considerably from it. This, 
caren Vs among other points, dis- 
| for tinguishes the stem from 
| ) a the root. We have also 
| \ iy seen that stems often 
bear adventitious roots 
(fig. 4), but this is not of 
primary importance, at 
least from a morphologi- 
cal point of view. 
Stem and leaf are so 
constantly associated that 
it is impossible to treat 
of one without reference 
tothe other. <A collective 
name, that of shoot, has 
; therefore been given to 
el | the stem with its leaves. 
The broadest grouping 
Hy dt that can be made of plant 
HT members divides them 
into only two sets, viz., 
roots and shoots. 
The regions of the stem 
to which leaves are at- 
tached receive the name 
of nodes, while the in- 
tervening portions are 
known as_ ¢énter-nodes. 
Nodes are often thick- 
ened, and adventitious 
roots generally arise from 
them. Where a leaf joins 
the stem there is an upper 
angle formed (usually 
acute), and a lower angle 
(usually obtuse) The 
former is known as the 
Ww Ff axil of the leaf. This 
Fic. 4.—Diagrammatic ee Sse bets a point is mentioned here 
Young Maize Plant (Zea mais) [from Sachs]. W. pri- : : 
mary root; ¢, #’, 6”, @”. adventitious roots spring- because ub is the rule 
ing endogenously from the ee (SE B he ; , ae m flowering plants for 
leaves, cut off short; b’’. young leaves of the termina : 
bud; &, &. axillary buds. The growing points are branch stems to arise 
represented black, the elongating parts grey; the in leaf-axils (fi ms, 3B) A, 
parts left white are fully grown. The white tips of é 
~ and 35). Such branches, 
the root are root-caps. 
