174 



FLORAL ENVELOPES. CALYX. 



angular or prismatic form, as in Lamium and Primula, and then the 

 angles are marked by the midribs of the sepals which form it. 

 Occasionally the calyx has a globular form, at other tunes it is bell 

 shaped, funnel-shaped, turbinate (like a top), or inflated. 



363. Occasionally, certain parts of the 

 sepals undergo marked enlargement. In the 

 Violet, the calycine segments (lacinice) are pro- 

 longed downwards beyond then 1 insertions, 

 and in the Indian Cress (Tropoeolum) this 

 prolongation is in the form of a spur (calcar), 

 formed by three sepals (fig. 275, e); in Del- 

 phinium it is formed by one. When one or 

 more sepals are thus enlarged, the calyx is 

 calcarate or spurred. In the Pelargonium, the 

 spur from one of the sepals is adherent to the 

 flower-stalk. 



364. In some plants as the Mallow tribe, the flower appears to be 

 provided with a double calyx, which has been denominated caliculate 

 the outer calyx being the epicalyx. In fig. 274, c represents the calyx 

 of Hibiscus, and b the smaller calyx or epicalyx outside; and in fig. 



276, the same thing is shown in Potentilla verna. 

 Many authors look upon the outer calyx as a col- 

 lection of whorled bractlets, or an involucre placed 

 immediately below the flower. In some cases the 

 projecting teeth between the divisions of the calyx, 

 as in Kosaceae, are to be traced to the transformed 

 stipules of the calycine leaves. Degenerations take 

 276 place in the calyx, so that it becomes dry, scaly, and 



glumaceous (like the glumes of grasses), as in the Rush tribe; hairy as 

 in Composite; and a mere rim, as in some Umbellifera and Acanthaceae, 

 when it is called obsolete or marginate. 



365. In Compositae, Dipsaceaa, and Valerianaceas, the tube of the 

 calyx adheres to the pistil, and the limb is developed in the form of 

 hairs, called pappus. This pappus is either simple (pilose) (fig. 278), 

 or feathery (plumose) (fig. 279). In cases where, to the naked eye, the 

 hairs appear to be simple, the application of a lens sometimes exhibits 

 distinct tooth -like projections often irregularly scattered. In figs. 

 277, 278, and 279, there are examples of calyces, c, the tubes of 

 which, t, are united to the pistil, while the limbs, I, show a transition 

 from the narrowed thread-like form in Catananche caarulea (fig. 277), 

 to the pilose in Scabiosa atro-purpurea (fig. 278), and thence to the 

 plumose in Pterocephalus paltestinus (fig. 279). In Valeriana, the 

 limb of the calyx at first seems to be an obsolete rim, but as the fruit 



Fig. 275. Calcarate calyx of Tropoeolum or Indian cress, e, Spur or calcar. p, Pedicel. 

 Fig. 276. Calyx, c c, of Potentilla verna, with its epicalyx or caliculus, b 6. 



