328 



MOXOCOTYLEDONES. 



Family 7. Gynandrse. 



The flowers are hermaphrodite and constructed on the ordinary 

 3-merous, pentacyclic type with petaloid, epigynous, strongly zygo- 

 morphic perianth, and generally one-stamened by the suppression 

 of the other 5 stamens. The family has derived its name from 

 the fact that the stamen is united with the style into a " stylar 

 column " (except Burmanniacece,} . All are herbs; many grow as 

 epiphytes on other plants. 



This family and the Scitamineas occupy correspondingly high positions 

 among the Monocotyledons ; these two families may therefore be placed close 

 together, although one cannot be derived from the other. The first of the two 

 orders is very small, but the second is very rich in species. The Apostasies 

 are best classed with the Orchidaceas and have no independent place. 



Order 1. Burmanniaceae. This order forms a transitional 

 link between the Gynandra? and the epigynous Liliiflorse (Ama- 

 ryllidacece), in having 1 a 6-leaved perianth, and 6-3 stamens ; but- 

 some have a labiate perianth (the median perianth-leaf of the outer 

 whorl being very large). The ovary is most frequently unilocular 

 with three parietal placenta? ; but in some it is 3-locular with axile 

 placentation. Capsule. Seeds oo, small, with endosperm. The 

 relationship to the Orchidacere is shown especially in the very 

 imperfectly developed embryo and in the ovary. Small, tropical 

 herbs (59 species) ; some are saprophytes. 



Order 2. Orchidaceae. The epigynous, petaloid peria.nth is 



strongly zygomorphic in 

 having the posterior leaf 

 of the interior whorl, the 

 lip (labellum), diffei-ing 

 from all the other leaves 

 in form, size, and colour 

 (except Apostasies} ; the 

 position of the labellum is 

 very frequently reversed, 

 being turned fonoards and 

 downu-anls by the twisting 

 of the ovary (Fig. 318 A). 

 Only 1 of the stamens 

 the anterior of the external 

 whorl is developed and 

 bears an anther (by the 

 twisting of the ovary it is 



B 



FIG. 318. A Diagram of an Orchid-flower. B, 

 Cephalanthera. Stylar-column : a antlier; ,< stigma ; 

 at the foot are seen scars indicating the position of 

 the parts which have been removed. 



