50 ARACEAE 



!>y heat. The rhizomes of many sp. contain much starch and are used 

 as food (Caladium, Colocasia, Arum, &c.). 



Classification and chief genera (after Engler) : 



The grouping of the A. is very difficult and account has to be taken 

 of histological as well as external characters. 



I. POTHOIDEAE (land pi. ; no latex or raphides ; 1. 2-ranked 



or spiral ; lat. veins of 2nd and 3rd order netted ; fls. usu. 5 ; 

 ov. anatr. or amphitr.): Pothos, Anthurium, Acorus. 



II. MONSTEROIDEAE (land pi.; no latex; raphides; lat. 



veins of 3rd, 4th, and sometimes 2nd orders netted ; fl. 5, 

 usu. naked ; ov. anatr. or amphitr.) : Rhaphidophora, 

 Monstera, Spathiphyllum, Epipremnum. 



III. CALLO1DEAE (land or marsh pi.; latex; fl. usu. ?; ov. 



anatr. or orthotr. ; 1. never sagittate, usu. net-veined) : 

 Symplocarpus, Calla. 



IV. LAS1OIDEAE (land or marsh pi.; latex; fl. $ or <? 2 ; 



ov. anatr. or amphitr.; seed usu. exalbum.; 1. sagittate, 

 often much lobed, net-veined) : Dracontium, Amorpho- 

 phallus. 



V. PHILODENDROIDEAE (land or marsh pi.; latex; fl. 

 naked, unisex.; ov. anatr. or orthotr.; seed usu. album.; 

 1. usu. ||-veined) : Philodendron, Zantedeschia. 

 VI. COLOCASIOWEAE ( land or marsh pi.; latex; fl. naked 

 unisex.; sta. in synandria ; ov. orthotr. or anatr.; seed 

 album, or not ; 1. net-veined) : Remusatia, Colocasia, 

 Alocasia, Xanthosoma. 



VII. AROIDEAE (land or marsh pi.: latex; 1. various, net- 



veined ; stems mostly tuberous ; fl. unisex., usually naked ; 

 sta. free or in synandria; ov. anatr. or orthotr.; seed 

 album.): Spathicarpa, Arum, Dracunculus, Helicodiceros, 

 Arisaema. 



VIII. P1ST10IDEAE (swimming pi.; no latex; fl. unisex., 



naked ; $ fls. in a whorl, ? sol.) : Pistia (only genus). 

 For further details of this most interesting order, see Engler in 

 Nat. Pfl. and Pfl. R-, from which much of the above is abridged. 

 [Placed in Nudiflorae by ff.} 



Arachis Linn. Leguminosae (in. 7). 10 Brazil, Paraguay. A. hypo- 

 gaea L. (ground-, earth-, or pea-nut), largely cult, in warm regions for 

 its seeds, which are ed. and when pressed yield one of the many oils 

 used in place of olive oil. The fl. after fert. bends down (cf. Linaria) 

 and the elongation of its stalk forces the young pod under ground, 

 where it ripens. 



Arachnanthe Blume (Renanthera p.p. EP.). Orchid, (n. 20). 10 S.E. 

 As., Malaya. 



Arachnites F. W. Schmidt = Ophrys L. (Orchid.). 



Arachnitis Phil. Burmanniaceae. i Chili. 



Arachnoid, cobweb-like. 



Arachnopogon Berg. Inc. sed. Nomen. 



Aracium Neck. = Crepis L. (Compos.). 



Araeococcus Brongn. Bromeliaceae (4). i Guiana, N. Brazil. 



Aragallus Neck. = Astragalus Tourn. (Legum.). 



