ARRANGEMENT. j 83 
a. The vernation of the leaf is exhibited in a most interesting manner, by 
making, with a keen instrument, a cross-section of the bud in its swollen state, 
just before its expansion; or it may be well observed by removing the scales. 
217. The forms of vernation are mostly similar to those of xstivation (108), 
and are expressed by similar terms. Some of the principal are the following: 
5 1. Equitant, overlapping each 
£ 3 
OO) (CHS) other in a parallel manner, with- 
: out any involution, as in the 
leaves of the Iris. 
\ 2. Obvolute, one of the margins 
of each leaf interior and the 
mf Sos G 2 other exterior to the margin of 
the leaf opposite. Ex. sage. 
FIG. 27.—Forms of vernation. The numbersagree 3. Involute, having the edges 
with the corresponding paragraphs. rolled inwards. Ex. apple, violet. 
4. Revolute, the margins rolled outwards or backwards. Ex. willow, rosemary 
5. Convolute, the leaf wholly rolled up from one of its sides, as in the cherry. 
6. Plaited, each leaf folded like a fan. Ex. vine, birch. 
7. Circinate, when rolled downwards from the apex. Ex. sundew, fern. 
§2. ARRANGEMENT. 
218. In regard to their insertion upon the axis, the arrange- 
ment of the young leaves in the bud is nearly or quite circular, 
but by the development of the axis, this arrangement is modi- 
fied in various ways, and the leaves are then said to be 
1. Scattered, or uregular, as in the potatoe. 
2. Alternate, one above the other,on opposite sides. Ex. pea. 
_ 3. Opposite, two against each other at the same node (172). 
Ex. Hydrangia. 
4. Verticillate, or whorled, more than two in a circle at each 
node. Ex. meadow lily. 
5. Fasciculate, or tufted, in crowded whorls, or spires. Ex. 
Callitriche. 
219 We have formerly shown how some of these modes of arrangement may 
be reconciled with the spiral (174, a), and we here add, that, in general, when the 
leaves are said to be scattered or alternate, they will be found, by the attentive 
observer, to be strictly, though perhaps irregularly, spiral; always so in the 
annual shoot. 
a. Thus in the potato-vine, above cited, or in the house-leek, poplar, &c., if we 
commence at the lower leaf, and draw a line to the next above it, thence.to the 
next. and so on to the sixth leaf, we shall have gone just once around the stem, 
8 
