CONTRIBUTIONS FROM THE GRAY HERBARIUM OF HARVARD 

 UNIVERSITY. — NEW SERIES, NO. XXXIX. 



By B. L. Robinson. 



Presented March 8, 1911. Received May 4, 1911. 



I. ON THE CLASSIFICATION OF CERTAIN EUPATORIEAE 



Ageratum Gaumeri, sp. no v., annuum erectum 4 dm. vel ultra alti- 

 tudine copiose ramosum modice pubescens ; caule tereti gracili medul- 

 loso ; ramis oppositis adscendentibus foliosis ; foliis ovatis acuminatis 

 crebre et regulariter crenato-serratis tenuibus 3.5-6 cm. longis 2.5-4 

 cm. latis utrinque viridibus basi integris rotundatis vix ad insertionem 

 petioli acuminatis, petiolo 1.5-2.2 cm. longo ; inflorescentia perlaxa in 

 ramulis singulis racemiformi, pedicellis 2-4 (usque ad 6) cm. longis 

 unicapitulatis cum bracteolis 1-4 filiformibus minimis munitis ; capi- 

 tulis oblate subsphaericis 7-9 mm. diametro ; involucri squamis linear- 

 ibus attenuatis costatis glabriusculis subaequalibus ; disco conico ; 

 corollis limbum versus caeruleis ; styli ramis longe exsertis pulcherrime 

 caeruleis ; achaeniis nigrescentibus 5-angulatis vix in angulis obscure 

 hispidulis 1.2 mm. longis ; pappi squamis 5, aliis saepissime breviori- 

 bus muticis, aliis in aristam longam desinentibus et achaeniam longi- 

 tudine subaequantibus. — Ageratum intermedium Millsp. Field. Col. 

 Mus. Pub. Bot. Ser. iii. 90 (1904), not Hemsl. — Izamal, Yucatan, Dr. 

 G. F. Gaumer, no. 395 (type, in Gray Herb.). From tbe species here 

 described A. iyitermed'mm Hemsl. differs in having stems of a decidedly 

 firmer texture, presumably perennial and of a more spreading habit. 

 The leaves are smaller and the heads are borne in rather compact 2-5- 

 headed long-peduncled cymes. Finally the pappus is much shorter. 

 From the common and somewhat variable annual species A. conyzoides 

 L., the plant here described differs much in habit, in its more finely 

 serrate leaves, greater smoothness, and especially in its loose open in- 

 florescence, which on the individual branches becomes somewhat 

 racemiform, 



Ageratum Peckii, sp. nov., annuum erectum fastigiatim ramosum 

 5 dm. altum foliosissimum glabrum ; radice fibrosa ; caule subtereti basin 

 versus crassiusculo nodoso, internodiis inferioribus brevibus, superiori- 



