ANGIOSPERMS. 



603 



parts from the typical flower represented in Fig. 406, which is itself the typical diagram 

 of Liliaceae. ^ is the diagram of Bambusa, which only deviates from the type in 

 the absence of the outer perianth-whorl which is indicated by dots. But in most other 

 Grasses {B) the posterior leaf of the inner perianth-whorl (this whorl appearing generally 

 only in the form of small colourless scales), the whole of the inner whorl of stamens, and 

 the anterior carpel, are also wanting. In Nardus again (C), the anterior carpel only is 

 present (as far as the pistil is concerned) ; all the absent parts are represented by dots, 

 and the diagram is therefore so far a theoretical one. If the dots are removed, we get 

 the empirical diagram ; the number and position of the carpels is here determined from 

 those of the stigmas ^ 



FIG. 409.— L iagrain of the flower of a Grass ; A Bambusa; B of most Grasses ; C oi Nardus (from Doll, Flora von Baden, 



vol. I. pp. 105, 133). 



The flowers of Orchideae can also be derived, like those of Gramlneae, from the type 

 represented in Fig. 406, the empirical diagram of Liliaceae, although their external form 

 is so remarkably different. While in Grasses the perianth is especially degenerated or 

 even partially abortive, in Orchids both whorls are developed in a petaloid, and like the 

 whole flower, in a zygomorphic or monosymmetrical manner. Of the androecium, which 

 consists typically of two alternating whorls, each of three stamens, only a single stamen 

 is completely developed in most Orchids (Fig. 410, A)^ viz. the anterior one of the outer 

 whorl, the others being abortive. Indications of these are however sometimes found 

 in the young bud, as in Calanthe veratrifolia (according to Payer, cf. Fig. 394), where at 



FIG. 410.— Diagram of tlie flower of Orchideae ; A the ordinafy structure ; B that of Cypripedium (see Figs. 372 and 41J 

 the dots indicate stamens which are altogether abortive, the shaded figures rudimentary stamens which become abortive 

 transformed into staminodes. 



least the two anterior ones of the inner whorl (but not the posterior one) appear as 

 small elevations which soon disappear. In Cypripedium, on the contrary, a large 

 staminodium (see Fig. 372) takes the place of the anterior stamen which is else- 

 where fertile ; while the two anterior and lateral anthers of the inner whorl are fally 

 developed and fertile (Fig. 410, 5). In Ophrydeaj two small staminodes are found 

 beside the gynostemium {cf. Fig. 418, D^st) in the place of the two fertile stamens of 

 Cypripedium ; while in Uropedium all three of the inner whorl are completely developed. 

 (Doll.) The carpels which, by adhesion with the androecium form the gynostemium, are 

 developed unequally, a diflference which however is usually not discernible in inferior 

 ovaries, and is therefore not indicated in the diagram. The student who desires to 



1 Compare further, Doll, Beitrage, in the Jahresbericht des Mannheimer Vereins fiir Naturkunde, 

 1870, where an actual pentacyclic trimerous flower oi Streptoch<Bte is described. 



