ENDOGKNOUS OR MONOCOTYLKDOXOUS PLANTS. 



489 



of six parts ; their single fertile stamen (or in Cjpripedium tlieir 

 two stamens) coherent with the style (composing the column) ; their 

 pollen usually combined into two or more granular or waxy masses 

 (poUmia) ; the ovary one-celled, with three parietal placentae, 



1235 



1233 



1234 



1236 



covered with numerous minute seeds. — Ux. Orchis, Cypripedium 

 (Ladies' Slipper), Arethusa, &c. In the tropics many are Epiphytes 

 (149, Fig. 144). Many are cultivated for their beauty and singu- 

 larity. The tuberiferous roots are often filled Avith a very dense 

 mucilao'inous or glutinous substance (as those of our Aplectrura, 

 thence called Putty-root). Of this nature is the Salep of commerce, 

 the produce of some unascertained species of Middle Asia. The 

 fragrant Vanilla is the fleshy fruit of Vanilla planifolia and other 

 trbpical American species. The roots of Cypripedium are used as 

 a substitute for Valerian. 



938. Ord. Zingiberacece {Ginger Family) consists of some mostly 

 showy tropical aromatic herbs, the nerves of their leaves diverging 



FIG. 1233. Orchis spectabilis : a, a separate flower. 1234. Column (somewhat magnified), 

 from which the other parts are cut away : the two anther-cells opening and showing the pollen- 

 masses. 1235. Magnified pollen-mass, with its stalk. 1236. Arethusa bulbosa. 1237. The 

 column, enlarged : the anther terminal and opening by a lid. 1238. Magnified anther, with 

 the lid removed, showing the two pollen-masses in each cell. 



