GROUP V. AXGIOSPERALE ; MOXOCOTYLEDOXES. 



503 



the narrow ones vary in number in the different species (Fig. 314 a 

 and /?) : seed without endosperm ; seeds numerous in Canna, single 

 in each loculus in other genera. 



Canna indlca and other species are com- 

 monly grown as ornamental plants. 



Amylum Marantse, the starchy meal 

 prepared from the rhizome of Maranta 

 arundinacea.is true or West Indian arrow- 



Cohort IV. Orchidales. Flower 

 irregular, dorsiventral, zygomorphic, 

 gynandrous (see pp. 455, 462), reduced 

 iii the androecium : perianth petaloid. 

 Seeds very small, without endosperm 

 or perisperm ; the embryo a minute 

 undifferentiated mass of cells. 



Order 1. ORCHID ACE^E. The flowers 

 of most of the genera have the for- 

 mula ^ A'3, C3, 41 + f 2, m : those 

 of the Cypripediinse, however, have 

 the formula -^ K3, C3, A f 1 + 2, 0$ 

 (Fig. 315 A, B}. The flower is gene- 

 rally 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, 

 Epipogum). The posterior segment (petal) of the inner whorl called 

 the labdlum (Fig. 31 6, see also Fig. 244 I), is always larger than 

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

 (Fig. 316 sp) or a sac-shaped cavity (Fig. 244). The andrcecium 

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

 of the floral axis the gyuostcmium (Fig. 244 s ; Fig. 318 B and C gs). 

 In the androecium usually three stamens are represented : in the 

 mouandrous Orchids there is a fertile anterior stamen belonging to 

 the outer whorl (Fig. 315 .4), and often two staminodes, which 

 are sometimes petaloid (e.g. Diuris) or small tooth-like prominences 

 (auriculae, stelidia) on the gynostemium (e.g. Orchis, Epipactis, 

 Fig. 244 a?), belonging generally to the inner androecial whorl, 

 but sometimes apparently to the outer : in the diandrous Orchids 

 (e.g. Cypripedium, Fig. 315 B) there are, generally, two fertile 

 stamens belonging to the inner whorl ; the outer whorl being only 



Fio. 314. Flower of Caima indiea 

 (nat.size) : /inferior ovary ; pa the 

 outer; jn the inner whorl of the 

 perianth ; g style ; tt the fertile sta- 

 men, with (<ui) the anther ; I label- 

 lam ; a and ft the two staminodia. 

 (After Eichler.) 



