GROUP TV. — PHANEROGAMIA: ANGlOSPERMj; : MONOCOTYLEDONES. 563 



a bilocular anther (Fig. 368 st, an) ; of the staminodia one is 

 larger than the others, and is reflexed, forming a lahellum (Fig. 

 368 /) ; the narrow ones vary in 

 number in the different species 

 (Fig. 368 a and /3) : seed without 

 endosperm ; seeds numerous in 

 Canna, single in each loculus 

 in the other genera. 



Canna indica and other species are 

 commonly grown as ornamental 

 plants. 



Amylum Marantae, the starchy meal 

 prepared from the rhizome of Maranta 

 arundinacea, is true or West Indian 

 arrowroot. 



Cohort 4. Orchidales. 

 Flower irregular, dorsi ventral, 

 zygomorphic, gynandrous (see 

 pp. 495, 518), reduced in the 

 androecium : perianth petaloid. 

 Seeds very small, without en- 

 dosperm or perisperm; the 

 embryo a minute undifferen- 

 tiated mass of cells. 



Order 1. Orchidace.e. The flowers of most of the genera have 

 the formula \ 7i3, C3, ^l + f 2, G-^/. those of the Cypripediina), 

 however, have the formula >|< K'd, OS, A f 1 + 2, G-(^^ (Fig. 369 

 A, B). The flower is generally so placed, in consequence of 

 torsion of the ovary, that the posterior side of the flower, instead 

 of being uppermost, as is normally the case, comes to lie inferiorly 

 (resupinate), but there are exceptions (e.g. Liparis, Nigritella, 

 Epipogium). The posterior segment (petal) of the inner whorl 

 called the lahellum (Fig 370, see also Fig. 294 l\ is always larger 

 than the others, and varies greatly in form ; it frequently has a 

 spur (Fig. 370 sp) or a sac-shaped cavity (Fig. 294). The an- 

 droecium and the three stigmata are, in most Orchids, borne on a 

 prolongation of the floral axis the gynostemium (Fig. 294 s ; Fig. 

 372 1/ and gs). In the androecium usually three stamens are 

 represented : in the monandrous Orchids there is a fertile an- 

 terior stamen belonging to the outer whorl (Fig. 369, A), and 

 often two starainodes, which are sometimes petaloid {e.g. Diaris) 



Fig. 368. — Flower of Canna, indica (nat. 

 size) :/ inferior ovary; pa the outer; jn the 

 inner whorl of the perianth ; g style ; st the 

 fertile stamen, with (an) the anther; I lahel- 

 lum ; a and )3 the two staminodia. (After 

 Eichler.) 



