DRUDEOPHYTUM 229 



Drooping 1 of young' 1., Aesculus, Bauhinia, Cinnamomum, Dryoba- 

 lanops; of young shoot, A/nherstia, Brownea, Saraca. 



Dropper, young immature bulb. 



Dropseed grass (Am.), Sporobohts, Muhlenbergia. 



Dropwort, Filipendttla vitlgaris Moench. ; water-, Ocnanthe. 



Drosera L. Droseraceae. 90 trop. and temp. 3 in Brit, (sundew). 

 D. rotund if olia L. abundant in bogs. Herbs usu. with creeping 

 rhiz. and rosettes of 1., insectivorous. The blade of the 1. is circular 

 in some sp., elongated in others, and is set with curious tentacles; 

 these are emergences containing vascular bundles and ending in 

 swollen reddish heads which secrete a sticky glistening fluid. Flies 

 and other insects mistaking it for honey are held by it. The tentacles 

 are exceedingly sensitive to continued pressure even by the lightest 

 bodies ; the result is to cause an inward and downward movement 

 of the head of the tentacle, finally placing the fly upon the blade 

 of the 1. At the same time the stimulus passes to the surrounding 

 tentacles causing them also to bend downwards to the same point. 

 The victim is thus smothered and now the glandular heads of the 

 tentacles secrete a ferment which acts upon the proteitls and brings 

 them into solution, when they are taken up by the 1. Afterwards 

 the tentacles expand once more and recommence the secretion of 

 the sticky fluid. The food thus obtained is of benefit to the pi., 

 though it can live without it. D. is able to live in very poor soil. 

 The extra materials obtained are devoted chiefly to seed-production. 

 If the stimulus produced by the capture of an insect be very power- 

 ful, the 1. itself may bend into a cup form, and this feature is very 

 marked in some sp. , the 1. bending almost double over the prey. 

 The fls. of the Brit. sp. rarely open, but self-pollinate in bud. 



Droseraceae (EP., BH.}. Dicots. (Archichl. Sarraceniales ; Resales 

 BH.}. 5 gen., too sp. , Drosera cosmopolitan, the rest more local. 

 Herbs, usu. with perenn. rhiz. and rosettes of 1. ; Aldrovanda a 

 water-plant. All are insectivorous ; Dionaea and Aldrovanda have 

 sensitive 1. which shut up when touched, the others catch their 

 prey by sticky tentacles upon the 1. (see genera). Us. usu. in cin- 

 cinni, rarely in racemes or sol., $, reg. , 5 4-merous, usu. hypog. 

 K (5) ; C 5, imbr. or conv. ; A usu. 5, pollen in tetrads (cf. Erica- 

 ceae); G (2, 3, or 5) ; plac. usu. parietal, rarely axile or free-central ; 

 style long ; stigmas simple or branched ; ov. 3 oo , anatr. Loculic. 

 caps. ; seed with endosp. and small basal embryo. Genera: Dionaea, 

 Aldrovanda, Drosophyllum, Drosera, Roridula. 



Drosophyllum Link. Droseraceae. D. liisitanicum Link, Morocco, 

 Portugal, S. Spam. The 1. have glands of two kinds stalked, 

 secreting a sticky fluid (cf. Drosera), and sessile, which only secrete 

 when stimulated by nitrogenous matter, and then secrete a digestive 

 ferment. Insects alight on the glands and are entangled; they 

 struggle for a while and finally sink down and die, and are digested 

 by the ferment. The taller glands have no power of movement, 

 but are able to secrete a ferment as well as the sessile ones. 



Drudea Griseb. Caryophyllaceae (i. 3). i Peru. 



Drudeophytum Coulter et Rose (Arracacia p.p.). Umb. (in. 4). 

 ? N. Am. 



