184 



COROLLINE APPENDAGES. 



disappears from the rest of the plant. What have usually, however, 

 been called Nectaries, are mere modifications of some part of the flower, 

 produced either by degeneration, or by a process of dilamination (dis, 

 separate, and lamina, a blade), or chorization (%u^<a, I separate). 

 This process, called unlining by Lindley, and deduplicatwn by Henfrey, 

 consists in the separation of a layer from the inner side of a petal, 

 either presenting a peculiar form, or resembling the part from which 

 it is derived. The parts thus produced are not alternate with the 

 petals or the segments of the corolla, but opposite to them. In these 

 cases, the petals at the lower part consist of one piece, but where 

 the limb and claw separate, or where the tube ends, 

 the vascular layer splits into two, and thus two 

 laminae are formed, posteriorly and anteriorly, one 

 of which is generally less developed than the other. 

 These dilaminated scales are well seen in Lychnis (fig. 

 303 a), Silene, Cynoglossum, and Ranunculus, and 

 may be considered as formed in the same way as the 

 ligule of grasses (^[ 161). Corollas having these scaly 

 appendages, are sometimes denominated appendiculate. 

 In other cases, as in Cuscuta, the scales are alternate with 

 the petals, and are not traced to dilamination. This 

 system of dilamination has been applied by the French 

 botanists to all cases in which the parts of whorls be- 

 come opposite in place of alternate. Lindley and others, 

 however, believing that the law of alternation is the 

 normal one, refer such cases in general to an abortion 

 of a whorl, or to some peculiar arrestment in development, as will be 

 shown under the section of Morphology and Symmetry. 



384. In general, the parts called Nectaries, are to be 

 considered as merely modifications of the corolla or 

 stamens. Thus, the horn-like nectaries under the 

 galeate sepal of Aconite (fig. 284 p), are modified 

 petals, so also the tubular nectaries of Hellebore. The 

 nectaries of Menyanthes and of Iris, consist of hairs 

 developed on the petals. Those of Parnassia (fig. 304 

 /i), and of the Passion-flower, Stapelia, Asclepias, and 

 Canna, are fringes, rays, and processes, which are ap- 

 parently modifications of stamens, and some consider 

 the crown of Narcissus as consisting of a membrane 

 similar to that which unites the stamens in Pancratium. 

 It is sometimes difficult to say whether these nectaries 



Fig. 303. Petal of Lychnis fulgens, seen on its inner side, o, Claw. I, Limb, a, An appen- 

 dage formed by dilamination or chorization. This appendage has been called a nectary. 



Fig. 304. Petal, p, of Parnassia palustris, or grass of Parnassus, with a nectary, n, which ap- 

 pears to be an abortive state of some of the stamens. 



