1960] 



BOTANY OF THE GUAYANA HIGHLAND PART IV 



5 



late obtusa, 3-4 mm longa, 1 mm lata; marginibus inferne erectis, superne in- 

 volutes, in sectione transversali leucocystae ubique biseriatae, limbo basilari 

 (lamina vera) e seriebus 4—6 lato. Caetera ignota. 



VENEZUELA: Bolivar: Chimanta Massif, Bonnetia swale along creek just east of west 

 branch of headwaters of Rio Tirica, terrestrial, alt. 2120 m, 11 Feb. 1955, Steyermark $ Wur- 

 daek 726 (type) ; elfin forest formation on plateau of southeast-facing upper shoulder of 

 Apacara-tepui, terrestrial, alt. 2000 m, Steyermark 75719 (paratype). 



The short, ovate-lanceolate leaves tapering gradually to the rounded, cucul- 

 late apex with the leucocysts in two layers throughout the leaf make this a 

 unique species comparable with nothing I am familiar with. Cross sections from 

 the upper part of the leaf show the chlorocysts much nearer the dorsal side 

 while below they are nearly central. 



CALYMPERACEAE 



Syrrhopodon tenuifolius (Sull.) Mitt, 



VENEZUELA: Bolivar: Chimanta Massif, south-facing forested slopes above valley of 

 South Cano on summit, alt. 1955-2090 m, Steyermark $ Wurdaek 1119. 



Xew to Venezuela. 

 Syrrhopodon gaudichaudii Mont. 



VENEZUELA: Bolivar: Chimanta Massif, rocky slopes of zanjon bordering upper falls 

 of Rio Tirica above Summit Camp, alt. 1950 m, Steyermark 4' Wurdaek 615. 



Syrrhopodon rigidus Hook. & Grew 



VENEZUELA: Bolivar: Slopes and talus forest, Sarven-tepui, on liana stem in rain 

 forest near Camp 9, alt. 1200 m, Wurdaek 34357. 



New to Venezuela. 



POTTIACEAE 



Trichostomum duidense Bartr. 



VENEZUELA: Bolivar: Chimanta Massif, on large rock bordering savanna above Sum- 

 mit Camp, alt. 1940 m, Steyermark $• Wurdaek 426; thickets bordering savanna below upper 

 falls of Rio Tirica above Summit Camp, Steyermark 4' Wurdaek 616; slope forest above Rio 

 Tirica, alt. 1365-1670 m, Steyermark Wurdaek 1241; slopes and talus forest, Sarven-tepui 

 between Camps 3 and 4, alt. 1400 m, Wurdaek 34079. 



BRYACEAE 



Bryum curvifolium Bartr., sp. no v. 



Sat robustum, caespitosum, caespitibus fuscescentibus, vix nitidis. Caulis 

 2-3 cm altus, regulariter foliosus, inferne rufo-tomentosus. Folia sicca erecta, 

 leniter curvata, humida erecto-patentia, incurva, asymmetrica, supra medium 

 curvata, 2.5 mm longa, 0.5 mm lata, oblongo-lanceolata, breviter acuminata; 

 marginibus inferne integris, recurvis, superne planis, arete serratis ; costa in 

 aristam brevem, serratam excurrenti ; cellulis superioribus anguste rhomboideis, 

 marginalibus angustioribus, limbum indistinctum 2-3-seriatim formantibus, basil- 

 aribus brevioribus. Seta tenuis, 3 cm longa. Caetera ignota. 



VENEZUELA: Bolivar: Chimanta Massif, dense wet elfin forest formation of recumbent 

 branches just below southeast-facing upper shoulder of Apacara-tepui (between Riscobel 

 Ledema Camp, and plateau), alt. 1900-1950 m, Steyermark 75705 (type). 



The asymmetrical leaves curved to one side above the middle are unique and 

 comparable with nothing else I am familiar with. 



