GENERA FUMARIA AND RUPICAPNOS. 2951 
vegotative organs, to the influences of environment. This is often seen in 
the general habit, which, while perhaps normally markedly characteristic, i« 
readily modified and sometimes quite obscured under abnormal conditions. 
The foliage of many species shows distinct inherent differences, but 
throughout the genus it is exceedingly responsive to surrounding influences, 
always tending to become dwarfer and more compact, with narrower, thicker 
and more channelled segments under exposure, and larger and laxer in form, 
with more ample and flatter segments, in shade or in damp situations. In 
some species the lowest pair of leaflets is always shortly petioled, and in a 
few others the leaves are notable for long-inucronate or aristate segments, 
Both among the Grandiflore and the Parviflore, however, there are several 
species in which the leaves are not readily distinguishable. Hammar defines 
the leaves as bipinnatisect in the annual species, but in most of them they 
are irregularly 3- or occasionally even 4-pinnatisect in normal individuals. 
The relative length of the raceme and its peduncle (i.e. the part of the 
rachis below the lowest flower) is usually more or less constant in the different 
species, but it should be recollected that the two or three earliest racemes of 
a plant frequently show longer peduncles than any that follow them, and the 
later ones sometimes become less floriferous. 
The length of the pedicels, as seen in fruit, and their direction or curva- 
ture, are generally characteristic, but in the case of species where this organ 
is areuate-recurved in normal plants, it commonly becomes straight and 
divaricate in shade. 
The form of the bracts and their length as compared with the fruiting 
pedicels are fairly constant and important as affording specific characters, 
It generally happens, however, that the two or three lowest bracts in a 
raceme are somewhat longer than those above them; and occasionally plants 
of various species will be met with in which the pedicels throughout are 
abnormally short and the bracts relatively more than usually long. 
The sepals are valuable for diagnostic characters, for in form, size, and 
marginal dentation they usually show little variation in the same species, 
except that in shade an elongate condition sometimes obtains in which the 
margin may be either more or less cut than usual. 
The features of the corolla are of the first importance, but they 
are often obscured and have proved the greatest source of confusion 
in the genus. This confusion is largely due to the prevalence, especially 
in the section Grandiflora, of a tendency under unfavourable environ- 
ment to produce cleistogamous flowers with more or less depauperate 
corollas (Pl. 9, figs. 8-10). Such flowers always tend to be pale or 
whitish in colour, and are sometimes reduced to less than half their 
normal size; their outer petals remain coherent till the corolla falls, and 
the margins of these petals are often quite undeveloped. ^ Possessing 
no nectary, they are regularly self-fertilized, the sexual organs remaining 
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