138 



CL. AROIDE^ (brown). 



1. PiSTIA. 



17. Callopsis. 



Stem rarely woody. Leaves alternate, radical or cauline, usually with 

 sheathing petioles, net- or parallel- veined. Spathe open to the base or 

 the lower part convolute or tubular, wholly deciduous or persistent, or 

 only the tubular part persistent. 



A liirge order, of about 100 genera, and about 1000 species, chiefly concentrated 

 in the tropics of both hemispheres, very few in temperate regions. 

 -'Flowers unisexual. 

 ■J* Perianth none. 



Female part of spadix adnate to the back of the 

 spathe ; flowers unilateral. 

 Female flower or ovary solitary ; a floating herb 

 Female flowers or ovaries 3-12 

 Female part of spadix free from the spathe, 

 bearing flowers all round. 

 ;|; Spadix with a terminal appendix destitute of 

 flowers, but sometimes covered with filiform 

 processes or hairs ; herbs with a tuberous 

 rootstock. 



Leaves and flower? produced together (see 

 also Amorpliopliallus angolensis). 

 Leaves peltate, cordate- or sagittate- 

 ovate ; spadix monoecious ; ovary 

 1-celled ; ovules numerous on 

 parietal placentas 

 Leaves 3-partite, pedate, or with 

 several leaflets radiating from the 

 apex of the petiole ; spadix often 

 unisexual; ovary 1-celled; ovules 

 basal, orthotropous 

 Leaves and flowers produced at different 

 times. 

 Leaves pedate ; margins of the spathe 

 connate into a tube below ; spadix 

 with neuter organs above the 

 female flowers .... 

 Leaves 3-branched at the apex of the 

 petiole; branches dichotomously, 

 divided, piunatipartite ; spathecon- 

 volute below, except in^. Elliotii ; 

 spadix without neuter organs 

 J J Spadix without a terminal appendix. 



§Herbs with a tuberous rootstock or a thick 

 fleshy rhizome ; no distinct stem. (See 

 also Anubias, which has a creeping 

 rhizome.) 

 Spadix with barren organs (staminodes) 

 on the apical part. 

 Ovary 2-celled ; ovule solitary in each 

 cell ; anthers connate in pairs . 

 Ovary 1-celled ; anthers connate in 

 groups of 4r-8 .... 

 Spadix with barren organs (staminodes ?) 

 between the ovaries and fertile an- 

 thers, none on the apical part ; ovary 



8. COLOCASIA, 



3. Aris.i:ma. 



2. Saueomatum. 



4. Amorphophallus. 



5. Ztgantheea. 



10. Ti'PHONODOEUM. 



