138 BOTANY 
oxalis, it is obcordate. A kidney-shaped leaf, as in 
the kidney fern (Fig. 97), is termed reniform (lL. renes 
the kidneys). When the broad base of the leaf has 
pointed lobes extending like a spear horizontally, as 
in the case of the arum (Fig. 97), it is hastate (L. hasta 
a spear), but where the lobes extend downwards, as 
in the convolvulus (Fig. 97), the leaf is sagittate 
(L. sagitta an arrow). The spatulate or spoon-shaped 
form is seen in the daisy (Fig. 97) and in Coprosma 
spatulata. 
Where the petiole comes off, not from the edge but 
from the middle of the blade, as in the nasturtium 
(Fig. 97) and Mount Cook lily (Ranunculus lyalli) the 
leaf is peltate. If the leaf is considerably narrowed 
but still tapers towards the tip, as in the willow, peach, 
and tawa (Fig. 98) it is lanceolate, and where the blunt 
end is turned outwards, as in the hinau (Fig. 98) and 
akeake, it is oblanceolate. The native flax (Phormium) 
has a sword-shaped or ensiform (L. ensis a sword) leaf 
(Fig. 98). If the narrowing is further continued, the 
leaf becomes linear as is the case in the mingimingi 
(Cyathodes) and most grasses (Fig. 98). The strap-like 
form assumed by many sea weeds, and by the leaves 
of vallisneria is doubtless to prevent injury by moving 
water. Further reduction of the blade results in a 
needle-like leaf termed acicular (L. acus, a needle). 
This is well seen in pinus insignis (Fig. 98). 
This progressive reduction of the leaf blade is in 
almost all cases to adapt the plant to dry conditions 
by guarding against excessive loss of water by tran- 
spiration; though, in some instances, it guards against 
the effect of wind as well. 
The veining of leaves is of two main types, 
reticulate (L. rete a net) or net veined, and parallel 
veined. Most dicotyledons, as the dandelion, apple, 
madhoe and coprosma (Fig. 99) are net veined, while 
most monocotyledons, like the lily, grass, cabbage tree 
