THE CASE-SEED CLASS 391 



though sometimes spathaceous; flowers mostly regular; the ovary 

 corn-pound, superior or inferior; and seeds of moderate number 

 and mostly rnedium size. 



Sec formula of Liliales on pages 424, 425. 



153. The orchid family (Orchidaceae). Examples; vanilla 

 (Fig. 148 I, page 149) and lady's-.slippers (Figs. 212, 213, 

 page 220). 



See formulas of Cypripedium, Vanilla, and Orchidaeea; on pages 

 424, 42.5. 



Although in the flowers of this family we can recognize 

 the fundamental type of structure exhibited by the lily-like 

 families, it is here modified by many curious and elaborate 

 complications. , An orchid might be described as a lily with 

 irregular perianth, one or two stamens inserted upon the 

 style, the other four or five being suppressed or represented 

 by staminodes, and with an inferior ovary so twisted as to 

 bring the flower upside down. A flower thus turned is said 

 to be resupinate.^ However obscure the morphology of 

 special parts may sometimes appear, orchids may usually 

 be recognized as perennial herbs, with irregular, resupinate, 

 epigy nous flowers, having a petaloid perianth, one or ttoo stamens 

 adhering to the style, and a capsular fruit with exalbuminous 

 seeds. 



154. The orchid order (Orchidales or Microspermse) con- 

 tains but one other family. This agrees with the orchids in 

 comprising herbs similar to the epigynous families of the lily 

 order but forming innumerable seeds of exceedingly small size. 



See the formula of Orchidales on pages 424, 425. 



155. The monocotyl subclass (Monocotyledones) is made 

 up of seed-plants having a monocotyledonous embryo, en- 

 dogenous stem, and mostly parallel-veined leaves. Together 

 with the dicotyl subclass they constitute 



156. The case-seed class (Angiospermae) which includes 

 all the flowering plants forming their seeds in a case or ovary 



' Re-su'pi-nate < L. re, back; supinare, bend. The twist is indi- 

 cated in a formula by @ placed after T. 



