PHANEROGAMIA : FLOWERS. 341 



woody from the interspersion of many thickened, porous paren- 

 chyma cells, as in the species of Banksia and Dryandra (?). In 

 paleaceous perianths, the spiral and other vessels are not found 

 in the usually simple vascular bundles, and in hair-like perianths 

 even the vascular bundles themselves are wanting. 



151. The calyx only exists when a corolla occurs with it; it 

 therefore can never be confounded with it. It is always the external 

 of two dissimilar sets of envelopes. Its series of forms very much 

 resemble those of the perianth; perhaps it is not so frequently 

 delicate in structure and colour (as in the Scitaminece, Musacece, 

 Butomacece, Ranunculus, Trop&olum, &c.). Usually it consists of 

 one circle of sepals, more rarely of two (as in the JBerberidacece). 

 These sepals are always very simple, oval, or lanceolate, seldom 

 pinnatifid, very frequently broad at the base and tapering to a 

 point, or very small (denies calycis obsoleti) ; sometimes they appear 

 only as dry scales, or as tufts of hair (the pappus of the Composites). 

 Appendages seldom occur upon the sepals, but they are frequently 

 of hollow or concave form. The number of the sepals in each 

 circle is in Monocotyledons frequently three, more rarely four or 

 two ; in the Dicotyledons it is most frequently five, but also two, 

 three, or four (and, perhaps, sometimes more). Coherence of the 

 sepals with one another may occur in every way, but, so far as 

 my knowledge extends, never with the corolla and stamens, nor 

 with the germens ; that which is so called being quite an other 

 condition (which has been already explained ( 146.) as the in- 

 ferior germen). Both in free and in coherent sepals, regularity and 

 symmetry are met with, the latter often exhibit the bilabiate 

 structures. 



That which has been said of the structure of the perianth applies 

 also to the calyx, only that here green foliar sepals are the more 

 frequent. 



The definition of the calyx, rightly comprehended, presents no diffi- 

 culty whatever, and it is only necessary to give a few examples to guide 

 in observation. For this purpose we select the three-leaved calyx of 

 Canna exigua (fig. 195.), the four- leaved calyx of 1 satis tinctoria 

 (fig. 199.), the coherent form of Salvia patula (fig. 200.), and the un- 

 developed one (pappus) of Actinomeris alferntfolia (fig. 201.). The 

 development of the calyx, so far as it appears necessary, is exhibited in 

 Plate IV. in Passiftora princeps. 



152. The corolla, which only exists as the inner set of floral 

 envelopes accompanying a calyx, may be compared to a very deli- 

 cate and coloured perianth. So far as my knowledge extends, no true 

 corolla occurs perfectly green and resembling the leaves ; its series 

 of forms is greater than that of any other of the floral envelopes. 

 In the Monocotyledons it presents in general only simple, round, 

 oval, or lanceolate leaves, very seldom having claws. In the Dico- 



z B 



