38. IRIDACEAE 143 



22. Underground part of the stem a root-stock. Perianth red. Filaments as 

 long as or longer than the anthers. — Species 2. South Africa. Used 



as ornamental plants Schizostylis Backh. & Harv. 



Underground part of the stem a corm. Filaments short. — Species 35. 

 South Africa and mountains of Central Africa. Some are used as 

 ornamental plants Hesperantha Ker 



23- (5-) St3dc-branches undivided, very short or thread-shaped or somewhat 

 broadened at the top, but not petal-like, nearly always alternate with the 



stamens 24 



Style-branches more or less divided or petal-like, opposite the stamens. 

 Perianth with a short tube or without a tube. Fruit not enclosed by the 

 spathe 32 



24. Perianth with a distinct tube. Filaments free. Style-branches very 



short. Fruit, wholly or for the greater part, enclosed by the spathe. 



[Tribe ARISTEAE, Subtribe aristinae.] 25 



Perianth divided nearly or quite to the ovary. Style-branches usually 

 long. Fruit not enclosed by the spathe. [Tribe SISYRINCHIEAE.] 30 



25. Perianth-segments very unequal, the inner much larger than the outer, 



blueish, the outer black ; tube short. Spathes 2 — 3-flowered, solitary 

 or in corymbs. — ^Species i. South Africa (Cape Colony). 



Cleanthe Salisb. 

 Perianth-segments almost equal 26 



26. Stem and leaves without green colour. Leaves short, scale-like. Flowers 



in umbel-like cymes. Perianth white, with a short tube. — -Species i. 



Madagascar Geosiris Baill. 



Stem and leaves green. Leaves long, linear or sword-shaped. Perianth 

 blue, rarely yellowish or whitish 27 



27. Spathes 3- or more-flowered, solitary or in spikes racemes or corymbs. 



Herbs. Perianth with a short tube. — Species 30. Southern and tropical 



Africa. Some are used as ornamental or medicinal plants. Aristea Ait. 



Spathes i — 2-flowered. Undershrubs 28 



28. Perianth with a short tube and clawed segments, blue. Filaments long. 



Spathes in heads. — Species i. South Africa (Cape Colony). 



Klattia Bak. 

 Perianth with a long tube. Filaments short 29 



29. Perianth blue, glabrous, with a cylindrical tube. Filaments awl-shaped. 



Anthers small. Spathes solitary or in corymbs. — Species 2. South 

 Africa (Cape Colony). Used as ornamental plants. (Under Aristea Ait.) 



Nivenia \'ent. 



Perianth greenish-yellow, hairy outside, with a funnel-shaped tube. Fila- 

 ments flat. Anthers large. Spathes surroimded by empty bracts and 

 arranged in heads. —Species i. South Africa (Cape Colony). Used as 

 an ornamental plant ; the stem contains sugar. . . Witsenia Thunb. 



