191 



Leaves smooth, 5-12 to a growth: — 



Leaves ^1^ ft. long, 6-9 lin. thick, rather 



suddenly acute or obtuse at the apex, 



dull bluish-green or dull dark green ,.. 6. PhiUipsiae. 



Leaves |-2i ft. long, 3-4i lin. thick, 



gradually becoming very acute at the 



apex, deep grass green 7. gracilis. 



Stem of adult plants none or veiy short, never 



branching in the air. Leaves 3-6 to a 



growth, 2-ranI:ed, 2-5 ft. long, ^-l^ in, 



thick, not grooved : 



Leaves mostly stiffly erect and not very 



widely diverging, the longer or all 



gradually tapering to a very acute point 20. cylindrica. 



Leaves all more or less irregularly recurving 



or widely spreading, rather shortly or 



abrux^tly pointed 20, cylindrica var. 



:|::tLeaves with a distinct channel all down the face, 



continuous wdth the sheath, besides and lar^rer 

 than any grooves that may be present, but 

 in the central leaves of adult plants (except 

 perhaps in S. rorida and S. deserti) always 

 much narrower than the full breadth of 

 the leaf at the middle part. Flower-stem 

 branched in S. rorida, in all the others 

 (where known) unbranched and the flower- 

 clusters forming a spike-like raceme; — • 

 Channel with acute whitish or green edges 

 below, passing into obtusely rounded green 

 edges at the upper part of the leaf; some 

 leaves almost without a channel apart from 

 the furrows; flowers mostly 3-6 in a 

 cluster 



patula. 



16. i7}termcdia. 



*** ttt **« ttft ««4 fttf* 



Channel with acute edges from base to apex 

 of the leaf : — 

 Central leaves of adult plants with green 

 edges to the channel or with white or 

 red-brown edges only at the basal or 

 apical part of the leaf : — 

 Leaves 5-10 to a growth, widely spreading 

 in a fan-like manner, the outer being 

 horizontally recurved from the base; 

 central leaves of adult jilants §-!§ in. 

 thick, somewhat abruptly narrowed 

 into A short hard white point; flowers 



2—3 in a cluster ... 15. patens. 



Leaves 4-8 to a growth, erect, straight or 



slightly curved, ^-l in. thick, gradually 



tapering into the acute hard white 



point; flowers 4-10 in a cluster: — 



Leaves wdth 9-12 shallow furrows on 



the sides and back ; pedicels 3-3^ lin. 



long, jointed below the middle ... 13. deserti. 



Leaves (except fi'om age or when 

 withered) without furrows ; pedicels 

 2-2^ lin. long, jointed slightly above 

 the middle 14. variaiis. 



Central leaves of adult plants with reddish- 

 brown or white edges to the channel 

 nearly or quite up to the apex or at least 

 extending beyond the middle (in 13, 

 5. deserti, the length to which the red 



