70 CALYX. SEPALS. 



and, (2.) the accessory or tegumentary parts, which occupy the 

 circumference, and serve to protect the first. 



23. These tegumentary parts of ike flower constitute what is 

 called the perianth (from the Greek peri, around, and anthos, 

 flower) ; sometimes they are wanting entirely ; and at others 

 they are imperfect; hut in most instances they form around the 

 essential organs of infloresence two envelopes, the most external 

 of which is called the calyx (cup of the flower), and the second, 

 which is situate above, and within the preceding, is named 

 the corolla (from the Latin, corolla, a little crown) {figt. 81, 82, 

 83, 84). 



d 24. CALYX. The calyx 



or the external envelope 

 of the flower is composed 

 of a variable number of 

 appendages, analogous to 

 leaves, which are called 

 sepals ; they are arranged 

 nearly in a circle around 

 the inferior part of the 



Fig. 81. SECTION OF A FLOWER. flower (fig. 81 , 6, c). Their 



colour is generally green ; 

 their surface is furnished with stomata, and their structure is 

 similar to that of leaves. 



25. Sometimes all the se'pals are perfectly distinct and may 

 be separated without breaking their tissue ; in this case they con- 

 stitute a polyse'palous* calyx ; at other times they are joined, or 

 as it were glued together, in such a way that the calyx appears 

 to be formed of a single piece, and is then designated under the 

 name of monose'palous\ or gamose 'pafaus^ calyx (figs. 84, 89, 

 95 ). When this junction extends throughout the whole extent 



Explanation of Fig. 81. Vertical section of a polypetalous flower (of the 

 family of Rosacece), showing the relative position of its different parts: a, 

 the peduncle ; 6, the calyx ; c, division of the calyx ; rf, the corolla ; e, 

 the stamens ; /, the stigma ; o, the ovary. 



* POLYSE'PALOUS. From the Greek, polus, many, and se'pal having 

 many sepals. 



t MONOSE'PALOUS. From the Greek monos, single, and se'pal having a 

 single se'pal. 



t GAMOSE'PALOUS. From the Greek ^omos, marriage, and se'pal having 

 the se'pals united together, forming a single piece or sepal. 



23. What is a perianth ? 



24. What is a calyx ? 



25. What are sepals ? What is a polyse'palous calyx ? What is a mono- 

 sepalous calyx ? What is meant by an entire calyx ? What are the lobes 

 of the calyx ? What is a regular calyx ? What is an irregular calyx ? 

 What is a labiate calyx ? 



