LEAVES. AS7 
of flowers, becomes a raceme from the elongation of 
the pediceis. In Umbellifere a similar change occurs, 
by virtue of which sometimes the umbels themselves, 
and at other times the florets, are raised on unusually 
long stalks, as in Angelica Razoulzi, Carwm Carwi, 
Thysselinum palustre." In Composite, when affected 
by an analogous change, the capitulum assumes the 
appearance of a simple umbel, as in Hypocheris radicata, 
Senecio vulgaris, and other plants. 
In some of the double-flowered apples which have 
been previously alluded to, the flower-stalk is inordi- 
nately long when compared with the adjacent ones. 
Possibly in some of these cases the absence of the 
usual swelling of the upper part of the peduncle may 
be connected with its increased length. One of the 
most striking imstances of lengthened flower-stalk 
occurred in an apple flower, wherein there was no 
swelling beneath the calyx, while the latter was repre- 
sented by five perfect stalked leaves. 
Elongation of the leaves——In the case of water plants 
this change keeps pace with the corresponding growth 
of the stem, e.g. Ranunculus fluitans, and in terrestrial 
plants there are varieties termed longifohar, from the 
unusual leneth of the leaves. <A similar lengthening 
occurs in the involucral leaves of Umbellifere and Com- 
posite, changing very materially the general aspect of 
the inflorescence. Occasionally, also, the leaf-lobes of 
parsley (Apium Petroselinum) and other crested-leaved 
plants may be observed to lose their ordinary wavy 
form, and to be lengthened into flat riband-lhke seg- 
ments, as shown in fig. 207. 
The only further illustrations that it is requisite to 
give of such changes in this place are those occurring 
in lobed or compounded leaves, which, from a lengthen- 
ing of the midrib or central stalk, convert a digitate 
or palmate leaf into a pinnate one. In these instances 
1 See Cramer, ‘ Bildungsabweich,’ pp. 62—79, and Fleischer, ‘ Missbild. 
der Culturpflanzen.’ 
