IQ. ARACEAE II5 



1. Flowers hermaphrodite 2 



Flowers unisexual. . . : 5 



2. Perianth none. Ovary incompletely 2-celled with several ascending 



ovules. Climbing shrubs. Leaves stalked, lanceolate. — Species 2. 

 West Africa. Used as ornamental plants. {Raphidophora Schott). 



[Tribe MONSTEREAE.] Afroraphidophora Engl. 



Perianth of 4 — 6 segments 3 



3. Ovary i-celled. Ovules 2 or more. Tall herbs. Juice milky. Root- 



stock tuberous. Leaves sagittate; stalk prickly. — Species i. West 



Africa. Used for making salt. [Tribe LASIEAE.] Cyrtosperma Griff. 



Ovary 2 — 3-celled. Juice not milky 4 



4. Ovule one in each cell, ascending, inverted. Seeds exalbuminous. Climbing 



shrubs. Leaves stalked, lanceolate to ovate. Spathe oblong or ovate. — ■ 

 Species i. Madagascar and Comoro Islands. [Tribe POTHOEAE.] 



Pothos L. 

 Ovules several in each cell, pendulous, straight. Seeds albuminous. 

 Herbs with a creeping i^oot-stock. Leaves sessile, linear, sword-shaped. 

 Spathe linear, sword-shaped, forming a continuation of the flowering 

 stem, — Species i {A. Calamus L., sweet-flag). Introduced in the 

 Mascarene Islands. Yields tanning-materials and is used in the pre- 

 paration of perfumes, liquors, snuff, and medicaments. [Tribe ACOR- 

 EAE.] Acorus L. 



5. Perianth present 6 



Perianth none S 



6. Perianth cupular. Ovary i — 4-celled with 2 or more ovules in each cell. 



Juice milky. Leaves sagittate ; stalk not thickened near the middle. 

 Spathe-margins connate below. — Species 20. Central and South-East 

 Africa. [Tribe STYLOCHITOXEAE.] . . Stylochiton Leprieur 

 Perianth of 4 free segments. Ovary 2-celled with i ovule in each cell. 

 Juice not milky. Leaves pinnate ; stalk with a thickened joint near 

 the middle. Spathe-margins free. [Tribe ZAMIOCULCASEAE.] 7 



7. Stamens with free filaments ; anthers opening by sHts. Leaves several, 



once pinnate. Spathe upon a short stalk. — Species i. East Africa 

 and Mascarene Islands. Used as an ornamental plant. Zamioculcas L. 

 Stamens with united filaments ; anthers opening by pores. Leaf i, thrice 

 pinnate in the adult stage. Spathe upon a long stalk. — Species 2. 

 East Africa to the upper Congo Gonatopus Hook. fil. 



8. Stamens united throughout their length or almost so 9 



Stamens free or united in pairs or at the base only 17 



9. Female (inferior) part of the spadix adnate to the spathe, i-flowered. 



Stamens 2. Floating water-plants Juice not milky. — ■ Species i. 

 Tropical and South Africa and Egypt. Used medicinally. [Tribe 



PISTIEAE.] " Pistia L. 



Female part of the spadix free from the spathe, several-flowered. 

 Stamens 3 — 8, very rarely 2. Land- or marsh-plants. Juice milky. 10 



