20 INTBODUCTION. 



and ovary. Hence the three following important distinctions in the rela- 

 tive insertion of the floral whorls. 



Petals, or, as it is frequently expressed, flowers, are 



hifpoc/ynous {i.e. under the ovary), when they or the disk that bears them 

 are entirely free both from the calyx and the ovary. The ovary is then de- 

 scribed as free or superior, the calyx a,sfree or inferior, the petals as being 

 inserted on the receptacle. 



perigynous (i.e. round the ovary), when the disk bearing the petals is 

 quite free from the ovary, but is combined with the base of the calyx-tube. 

 The ovary is then still described as. free or superior, even though the com- 

 bined disk and base of the calyx-tuhe may form a deep cup with the ovary 

 lying ui tlie bottom ; the calyx is said to be free or inferior, and the petals 

 are described as inserted on the calyx. 



epiyi/nous {i.e. upon the ovary), when the disk bearing the petals is 

 combined both vsith the base of the calyx-tube and the outside of the ovary ; 

 either closing over the ovary so as only to leave a passage for the style, or 

 leaving more or less of the top of the ovary free, but always adhering to it 

 above the level of the insertion of the lowest ovule (except in a very few 

 cases where the ovules are absolutely suspended from the top of the ovary). 

 In epigynous flowers the ovary is described as adherent or inferior, the calyx 

 as adherent or superior, the petals as inserted on or above the ovary. In 

 some works, howe\'er, most epigynous flowers are included in the perigynous 

 ones, and a very different meaning is given to the term epigynous (for which 

 see below, p. 21), and there are a few cases where no positive distinction 

 can be di-awn between the epigynous and perigynous, or again between the 

 perigynous and hypogynous flowers. 



An inferior or adiierent ovary (or its inferior or adlierent portion) has 

 usually the appearance of a mere cavity in the somewhat enlarged summit 

 of the peduncle below the calyx and petals. And some modern botanists 

 propose to describe the lower part of the calyx, with the adherent petal- 

 bearing disk, in perigynous as well as epigynous flowers, as an enlargement 

 of the peduncle, hearinq, at the circumference or at the top, the calyx, petals, 

 and stamens, and, in the centre or within-nde, the ovary. As the only dif- 

 ference between the peduncle and its enlargements on the one side, and the 

 receptacle and its disks on the other, is that the-former bears the bracts and 

 calyx and the latter the rest of the flower, an enlarged summit of the 

 peduncle and a dish are morphologically the same thing. This proposed 

 mode of describing may be theoretically more correct, but the theory of ad- 

 herence explained above is tlie most usually adopted in our Floras. 



When there are no petals it is the insertion of the stamens that determines 

 the difference between the hypogynous, perigynous, and epigynous flowers. 

 ■ When there are both petals and stamens, 



in hypogynous flowers the petals and stamens are usually free from each 

 other, but sometimes they are combined at the base. In that case, if the 

 petals are distinct from each other, and the stamens are monadelphous, 

 the petals are often said to be inserted on or combined -with the staminal tube ; 

 if the corolla is gamopetalous and the stamens distinct from each other, the 

 latter are said to be inserted in the tube of the corolla. 



in perigynous flowers the stamens are iisually inserted immediately 

 within the petals, or alternating with them on tlie edge of the disk, but oc- 

 casionally much lower down within the cUsk, or even on the unenlarged part 

 of the receptacle. 



in epigynous flowers, when the petals are distinct, the stamens are 



