MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



20. Leaf-blades glabrous or rugulose. 



24. Inflorescence 1-flowered; leaves 1-6 em long, twisted. 



26. X. esmeraldac. 



24. Inflorescence few-many-flowered. 



25. Scape bicostate, aneipital. 27. X. tatei. 



25. Scape eeostate, terete to somewhat flattened. 

 2G. Leaf -blades 2.5-3.5 mm wide; spike obovoid, 11-13 (-15) 



mm long, many -flowered. 28. X. lugubris. 



26. Leaf -blades 0.5-1.5 mm wide. 



27. Blades flat, even. 29. X. scabridula. 



27. Blades terete, rugulose. 30. X. delicatula. 



6. Dorsal area of the bract clearly evident. 

 28. Leaf -blade terete. 



29. Spike 1-3-flowered, slenderly fusiform becoming obconic with age. 



30. Leaf-blade 0.2 mm in diameter, abruptly contracted from the glabrous 



sheath. 31. X. exserta. 



30. Leaf-blade 1 mm in diameter, merging with the ciliate sheath. 



32. X. fusiformis. 



29. Spike few-many-flowered; leaf-blade 0.2-2.4 mm in diameter. 



31. Leaf-sheaths ciliate. 



32. Bracts glabrous, acute; leaves smooth. 33. X. oxylepis. 



32. Bracts lanate, at least at the apex. 



33. Leaves scabrous; margins of the obtuse bracts clearly visible. 



34. X. garcia-barrigae. 

 33. Leaves smooth or irregularly sulcate when dry; margins of the acute 



bracts obscured by the copious white indument. 35. X. wurdacJcii. 



31. Leaf -sheaths glabrous. 



34. Plant aquatic; rhizomes elongate; leaves flaccid; sheaths w T ith an auricle 



2 mm long; sepals equilateral. 36. X. aquatica. 



34. Plant terrestrial; rhizomes short; leaves subrigid. 



35. Auricle of the sheath 8 mm long; sepals inequilateral. 37. X. terrestris. 

 35. Auricle of the sheath 1 mm long or less. 



36. Sheaths pale; sepals strongly inequilateral. 38. X. juncifolia. 



36. Sheaths dark castaneous; sepals equilateral. 39. X. neblinae. 



28. Leaf -blade linear, distinctly flattened. 



37. Spikes long and slender, much more than twice as long as broad. 



38. Bracts more than 2-ranked. 40. X. longiceps. 



38. Bracts 2-ranked. 41. X. stenostachya. 

 37. Spikes stout or short, mostly less than twice as long as broad. 



39. Bracts vestite, at least toward the apex. 



40. Bracts acute. 42. X. arachnoidea. 



40. Bracts broadly rounded. 



41. Leaf -blades 2-5 mm wide, strongly thickened on the margins; spike 



subglobose to cylindric, 10-35 mm long. 43. X. lomatophylla. 



41. Leaf -blades 1 mm wide, not thickened on the margins; spike globose 

 to ovoid or obovoid. 

 42. Sheaths abruptly orbicular-dilated and castaneous at the extreme 



base, elsewhere green. 44. X. globosa. 



42. Sheaths not dilated at the base, wholly dark-castaneous. 



45. X. lanulobractea. 



39. Bracts merely ciliate or completely glabrous. 



43. Spikes 1-3-flowered, slenderly fusiform, spreading to obconic with age; 

 bracts eciliate, the basal ones mostly about half as long as the spike. 

 44. Lateral sepals free. 



45. Bracts obtuse; leaf -sheaths glabrous. 46. X. yapobodensis. 



45. Bracts acute.* 



46. Leaf -sheaths glabrous. 



47. Blades 0.3-0.4 mm wide, not marginally thickened. 



47. X. cyperoides. 



47. Blades 1-2 mm wide, marginally thickened. 



48. Leaves transversely rugulose. 48. X. rugulosa. 



48. Leaves even or sulcate, not rugulose. 49. X. guianensis. 



