96 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



FLORAL ORGANS. 

 Calyx. 



Useful Changes. — The calyx as a rule is green in the bud and acts as 

 a protection to the internal organs. It is mostly homologous with the 

 petiole only of a leaf, as may be readily seen in a Rose-bud, in which the 

 imperfect leaflets are still present, but as functionless remnants of the 

 compound leaf. 



In some few instances the blade is present, as in the Corn-cockle. 



Sometimes the blades are restored abnormally as true leaves, when, 

 of course, they re-acquire the functions of normal foliage. Thus, in the 

 cultivated variety of Primrose known as ' Jack-in-the-Green,' the calyx 

 develops the limb, or blade, thereby becoming foliaceous, so that each 

 sepal is equivalent to a perfect leaf. 



The calyx may be either normally or abnormally coloured. Clematis, 

 Anemone, Caltha, and Hellebore have no corollas, the white or coloured 

 calyx undertaking to be the attractive organ instead. 



Abnormally, it is seen in the 1 Hose in hose ' form of Mimulus, 

 Azalea, Campanula (' Cup and Saucer '), and Primrose. 



In Hydrangea, the calyx is large, white or coloured ; but this is 

 secured at the expense of the other organs (corolla, stamen, and pistil) 

 becoming abortive ; so that no seed can be set, and the flowers are said 

 to be neuter. 



As a rule it is only the outermost flowers of the cluster which thus 

 render the whole attractive, so that the perfect but very inconspicuous 

 little flowers in the middle can be discovered and visited by insects. 



Useless Changes. — Degeneracy of the calyx to useless rudiments is by 

 no means uncommon. It may be even entirely suppressed. This is 

 especially the case when flowers of an inflorescence are much crowded. 

 Hence members of the families Dipsacece, Valcrianacece, Rubiacece, Com- 

 positce, and Umbelliferce are particularly characterised by having rudi- 

 mentary sepals, or none at all. In the Composites it is often represented by 

 hairs or the " pappus," when it re-acquires a use for dispersal. 



Some other useless changes or conditions of the sepals are seen in 

 malformations when the sepals try to be stamens or carpels. Such are 

 comparatively rare, but have been described in Philadelphia speciosus, in 

 which the sepals attempted to become stamens, and in double flowers of the 

 Garden Pea the sepals formed open carpels with rudimentary ovules. 



Corolla. 



Useful Changes. — The normal use of a corolla is as an attractive organ, 

 being visible to insects. It may, however, become green and foliaceous, 

 in which case its use is changed to that of leaves. 



Such occurs in the cultivated Green Rose and Alpine Strawberry, and 

 not infrequently with late flowers of the Wild Honeysuckle, &c. 



Useless Changes. — The wild Guelder Rose resembles the Hydrangea in 

 having the flowers on the circumference of the truss or corymb con- 

 spicuous but neuter, while the minute central flowers are perfect ; this is 



