193 



« 



8, rorxda. 



10. PerrotiL 



Stem 4-8 in, high; flower-stem paniculately branched 



above, (See also 9, S. zaTtziharica , of which the 



flowers are unknown) : 



Leaves of adult plants 1-2 ft. long, broadly 



channelled and somewhat half-cylindric at the 



basal part, becoming cylindric and narrowly 



channelled towards the apex 



Leaves of adult plants 3-5 ft. long, with a deep 

 concave channel as broad as the leaf throughout 

 its length 



**Stem none (or 9 S, zanziharica ' ' scarcely caules- 

 cent "); leaves with a channel down the face as 

 broad as the leaf and rounded or obtusely keeled 

 on the back; flower-stem, where known, un- 



branched and the flower-clusters arranged in a 

 spike-like raceme: — 



Adult leaves with reddish-brown edges to the 



channel throughout their length 9. zanzibarica. 



Adult^ leaves with green edges to the channel or 

 with white or red edges only for a few inches 

 at the base or apex : — 

 Central leaves of adult plants with slight but 

 evident grooves down the sides and back, half- 

 cylindric with a broad concave channel down 

 the face; flowers 2-5 in a cluster. (See also 

 26, S. Volkensii) 25. lanuginosa. 



Central leaves of adult plants without grooves on 

 the rounded back, except when withered, 

 4-10 lin. broad, 2^-t lin. thick, concave- 

 channelled down the face 27. zeylanica. 



(7. — Leaves either narrow and channelled, but in transverse section at 



their middle not more than 3-4 lin. thick, or fiat or slightly con- 

 cave and six to many times as broad as they are thick at the 

 mid-rihj never cylindric nor half-cylivdric; floicer-stem not 

 branched. 



*Edges of the leaves of adult plants green (or from 



rubbing or injury very narrowly whitish in 

 places, not all along), apex tipped with a soft 

 green subulate j^oint |-3^ in, long. 

 tLeaves of adult plants ^-IJ- (or in 35, S, subspi- 

 cata up to 2J) in. broad, 4-24 to a growth, 

 ^ deeply channelled, concave or flattish, broadly 



linear, strap-shaped or narrowly lanceolate: — 



Leaves linear or narrowly linear-lanceolate, and 



usually more than 1 (and up to 2^) ft. 

 long: — 



Central leaves of adult plants 2^-4 lin. thick 



at the middle, ascendinfj: or erect, rather 

 ngid : — 



Leaves straight, with several grooves down 



the hack, which are stated to be woolly... 25. lanuginosa. 



.^ 



t^es slightly recurving at the upper part, 

 not grooved on the back except when 

 withered, verv dark n^reen 



•• ••- #•• 



Central leaves of adult plants 1^-2 lin. thick 

 at the middle : — 



Central leaves sub-erectly or ascendingly 

 recurving, concavely channelled, rather 

 stiff 



27. zeylanica. 



' zo, lioxDuratiiana. 



Central leaves very erect, straightj^ flattish, 



with a slight angular channel, flexible... 29. hurmami 



4b 



