12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



upper part of the leaf, but there is no stereid baud. The species must 

 therefore be placed in section Pseudocampylopus ; it is the only 

 hair-pointed species at present known there. 



POTTIACEAE 

 HYMENOSTYLIUM CRASSINERVIUM Broth. & Dixon, sp. nov. 



(Plate 1, fig. 2) 



Stirps pro genere robusta, caespites densiusculos elatos usque ad 

 5 cm. altos, olivaceos, intra flavescentes formans, caulibus submolli- 

 bus flexuosis inter dum ramulosis interrupte foliosis, hie illic propa- 

 gitlis rliizoideis substrictis simpticibus elongatis robustis (ad I cm. 

 longis 70-80 j* latis) rubris, nunc laevibus nunc papillosis parce 

 vestitis. Caulis sectione sine fasciculo centrali, reti interno laxi- 

 usculo tenerrimo, externo e cellulis 2-3 seriebus stereideis vel sub- 

 stereideis rufo-fuscis composito. 



Folia 1.5-2 mm. longa, madida squarrosa vol recurva, sicca leniter 

 crispata, e basi paullo latiore perbrevi anguste ligulata, breviter nee 

 anguste acuminata, acuta, concavo-carinata, marginibus vel omnino 

 planis vel uno latere ad infimam basin brevissime angustissime 

 recurvo, superne saepe valde irregulariter minute sinuosis, nullo modo 

 denticulatis. Costa valida, basin versus ad 75 /x lata, in summo apice 

 evanescens, dorso laevis vel hie illic minute scaberula, fuscescens. 

 Cellulae superiores sitbqitadratae, pcUucidae, foliis junioribus chloro- 

 phyllosae, 8- 11 //. latae, tenerrime papillosae, parietibus firmis, vix in- 

 crassatis, basilares breviter rectangulares (2-4x1), pellucidae, pari- 

 etibus firmis. 



Cetera nulla. 



Forma robusta. Omnino robustior, ubique sordide olivacea, in- 

 ferne haud flavescens. 



Hab. : Vicinity of Thika, alt. about 1,350 meters, September 6 and 

 7, 1909, Nos. 1 143 (type), 1144. 



I submitted this plant, being uncertain of its position, to Dr. 

 Brotherus, who kindly wrote that in his judgment the stem and leaf- 

 sections indicated a Hymenostylium (rather than a Trichostomum). 



No. 1 144 consists entirely of the robust form, which is perhaps 

 worthy of a varietal name ; it is larger in all its parts, with the 

 stems darker rather than paler below, the leaves larger, denser, and 

 the whole plant more rigid. The leaves and stems vary, however, in 

 density or otherwise of arrangement ; both forms also occur in No. 

 1 143, where there are a few somewhat intermediate stems, so that 

 it is perhaps not more than an incidental form ; the leaf structure 

 presents no difference. 



