28 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 10 



41. Xyris stenostachya Steyermark, Fieldiana Bot. 28(1): 113. /. 16, K, L. 



1951. 



Type. Among rock outcrops, alt. 100 m, Sanariapo, Rio Orinoco, Amazonas, 

 Venezuela, Steyermark 58437 (isotype NY). 



Distribution. Frequent in moist sandy soil at low altitudes, chiefly above the 

 Great Bend of the Orinoco. VENEZUELA. Bolivar: La Urbana, Maguire & 

 Maguire 28989. Amazonas: Puerto Ayacucho, Maguire, Cowan & Wurdack 

 29243, Maguire, Wurdack & Bunting 36037 ; Yapacana Savanna, Maguire, 

 Cowan & Wurdack 30787 ; Cerro San Borja, Wurdack & Monachino 39845; 

 Salto de Humito, Rio Villacoa, Wurdack & Monachino 41164. 



42. Xyris arachnoidea Maguire & Smith, sp. nov. Fig. 12, A-E. 



Herbae acaules, cespitosae ; foliis 15-18 cm longis ; vaginis 3-4 cm longis, 

 sulcatis, rubescentibus, basi abrupte triangulari-auriculatis, apice eligulatis et 

 cum laminis confluentibus, intus longe denseque ciliatis, alibi glabris; laminis 

 linearibus, apice subacutis et leviter falcatis, 1.3 mm latis, glabris, sulcatis, rugu- 

 losis, margine haud vel vix incrassatis; scapo 20-33 cm alto, glabro, ad apicem 

 versus applanato, bicostato, 1 mm lato ; vagina scapi eis f oliorum simili, breviter 

 laminata ; spica obovoidea, 7-8 mm longa, pluriflora, dense arachnoidea ; bracteis 

 basilaribus valde reductis, alteris late ovatis, acutis, sepala subaequantibus, area 

 dorsali magna carinata praeditis ; sepalis lateralibus liberis, aequilateralibus, 

 lanceolatis, acutis, 5.5 mm longis, late carinatis, glabris ; placentis basilaribus, 

 elongatis. 



Type. Flowers yellow, occasional, Savanna III, northwest base of Cerro 

 Yapacana, alt. 150 m, Alto Rio Orinoco, 17 Mar 1953, Amazonas, Venezuela, 

 Bassett Maguire & John J. Wurdack 34570 (holotype NY, isotype US). 



Distribution. Known only by the type collection. 



43. Xyris lomatophylla Martius, Flora 24 2 : 57. 1841. 



Type. In campis Mfartius], Arara Coara [Amazonas, Colombia]. 



Distribution. Moist sandy savannas, Upper Orinoco and Rio Negro drainages. 

 COLOMBIA. Amazonas : Araracuara Savannas, Maguire, Maguire & Fernandez 

 44111, 44172; Vaupes : Cacagual Savanna, Rio Atabapo, Maguire, Wurdack & 

 Bunting 36394. VENEZUELA. Amazonas: Esmeralda, Tate 294 (NY); Yapa- 

 cana Savanna III, Maguire, Cowan & Wurdack 30476, 30477 ; Sabana El Venado, 

 Cano Pimichm, Rio Guainia, Maguire, Wurdack & Bunting 36359. BRAZIL. 

 Alto Rio Tapajos, southern Para, Egler & Eaimundo 952 (MG, US). 



44. Xyris globosa Alb. Nilss. Sv. Vet.-akad. Handl. 24 (14) : 57. pi. 3. 1892. 



Type. Prope Esmeralda ad flumen Orinoco, Spruce 3244 (holotype S, isotype 

 NY). 



Distribution. Thus far known only from Venezuelan Amazonas but is to be 

 expected to occur in Colombian Guayana also. Savannas of the middle and upper 

 Orinoco River. VENEZUELA. Amazonas : Esmeralda, Steyermark 57826 (NY) ; 

 Cerro Moriche, Rio Ventuari, Maguire, Cowan & Wurdack 30897, 30936, 30992; 

 Yapacana Savannas, Maguire, Cowan & Wurdack 30475, Maguire, Wurdack & 

 Bunting 36583 A; Sabana El Venado, Cano Pimichm, Maguire, Wurdack & Bunt- 

 ing 36360. Bolivar : Rio Orinoco between Rio Horeda & Cerro Gavilan, Wurdack 

 & Monachino 39952. 



