DEVELOPMENT OF PLANTS 405 



vated forms, as the iris, fleur-de-lis, crocus, gladiolus, friesia, 

 blue-eyed grass, etc. 



134. The Scitaminales.— This order is confined largely to the 

 tropics and includes such familiar plants as the banana, the trav- 

 eler's tree, ginger plant, canna, etc. It is mentioned here as fur- 

 nishing an interesting illustration of the variations that often 

 appear in epigynous flowers as a result of the crowding of the 

 organs upon the receptacle. Tendencies toward irregularity ap- 

 peared in the epigynous families of the Liliales, but in this 

 order these variations become very marked and make less abrupt 

 the transition to the next order. The flowers of the banana are 

 suggestive of the amaryllis family, though somewhat irregular. 

 All of the perianth leaves but one are united and only five per- 

 fect stamens are developed. These flowers are united into groups 

 in the axils of bracts that form large buds at the ends of the stem. 

 As the bud elongates, the basal or lower bract is first curved 

 back from the bud, thus exposing the flower cluster, and this 

 expansion goes on until all the flowers are exposed. The lowest 

 flowers in the inflorescence are imperfect, containing only pistils, 

 the central are perfect and the upper ones bear only stamens. 

 Only the ovaries of the lower flowers of the inflorescence develop, 

 each "hand" of bananas representing the matured ovaries of the 

 flowers in the axil of the bract. Singularly, seeds do not develop 

 in the edible banana, although you can see minute dark-colored 

 ovules forming three radiating lines in a cross-section of the 

 fruit. The ability of these plants to propagate themselves by 

 means of buds developed on the underground rhizomes may have 

 resulted in the loss of the seed habit. A great many plants are 

 so successful in propagating themselves by buds, bulbs, runners, 

 etc., that they have ceased to produce seed. In the higher mem- 

 bers of the order, as in the ginger and canna families, the flowers 

 become very irregular through the unequal development of the 

 leaves of the perianth or in some forms on account of the abor- 

 tion or transformation of all the stamens save one into petal-like 

 organs termed staminodia. Usually one of the leaves of the 

 perianth, or one or more of the staminodia, are highly modified 

 and known as the labellum. This organ is so placed as to afford 



