2 JOURNAL OF THE ARNOLD ARBORETUM [vol. i 



the curators of all these herbaria. For some mteresting material I am 

 indebted to Professor G. P. Clinton, New Haven, Conn., Miss A, Eastwood, 

 San Francisco, Professor J. K. Henry, Vancouver, B.C., Mr. I. M. Johnston, 

 Upland, Cal., and last, but not least to Mr. J. C. Nelson, Salem, Ore. 

 From the Herbarium of the University of Oregon, at Eugene, I have re- 

 ceived the Salix material of the Howell Herbarium. 



CLAVIS SPECIERUM VARIETATUMQUE 



Folia adulta^ semper utrinque concoloria, viridia, lincaria, hneari-lanceolata vel 

 lanceolata, utraque facie stomatibus plus minusve aequinumerosis (tantum in 

 quadani forma incerta S. nigrae paucioribus vel fere nulHs) instructa; petioli 

 (vel basis laminae) apice eglandulosi vel subeglandulosi (i.e. glandulis distinctis 

 flaveseentibus saepc irregulariter lobulatls baud praeditis, sed saepr glandulae 

 minimae punctiformes adsunt); ramuli fragilissimi .... Sect. I. Nigrae. 

 Hamuli annotini ^ biennesque plus minusve rufescentes vel purpurascentes; ovaria 

 pedicellique semper glabri. 

 Fructus perfecte maturi ^ ovoldei vel ovoideo-oblongi, apice vix vel tantum 

 breviter attenuati, pedicello brevi iis pleroque 4-5plo breviore glandulam 

 circ. 2plo superante suffulti; folia linearia vel lineari-lanceolata; petioli 

 laminae comparati satis longi; stipulae intus fere semper eglandulosac. 

 Flort'S feminei glandula tantum ventrali instructi. 



Folia distincte linearia, tantum versus apicem attenuata. 



1. S. Ilumholdtiana. 

 Folia plus minusve lineari-lanceolata, fere a basi ad apicem sensim attenu- 

 ata lb. S. Iluviboldtiaria var. stipulacea. 



Flores feminei glandulis 2 (ventrali et dorsali) instructi. 



le. S. Ilumboldtiana var. Martiana, 

 Fructus perfecte maturi ovoideo-subrostrati, apice satis attenuati, pedicello 

 satis variabili longitudine glandulam 2-5plo superante; folia lineari-lanceo- 

 lata a<l late lanceolata; petioli sacpe laminae com])arati breviores vel stipulae 

 intus plus minusve glanduliferae. 

 Ramuli hornotini vel petioli (saltcm superne) plus minusve distincte villosuli 

 vel folia plus minusve lanceolata basi obtusa, subrotunda vel breviter acuta 

 et petioli breves (id est quam latitude laminae hand longiores); stipulae 



intus eglandulosae 2. 6'. nigra et 2b. S, nigra var. altissima, 



Ramuli petioliquc eitissime glabrescentes vel folia plus miimsve linearia et 

 basim versus attenuata et petioli graciles satis longi; stipulae intus glandu- 

 liferae 2c. S. nigra var. Lindhcimerii. 



den. ^ NE., Herbarium of the New England Botanical Club. — O., Herbarium of the Gcol. 

 Surv. of Canada, Ottawa. — P., Herbarium of the Academy of S(ienee, Philadelphia. — Pu., 

 Herbarium of the University of Washington, Puhman, Wash. — Reno, Herbarium of the 

 Nevada Agric. Exp. Station, Reno, Nev. — St., Herbarium of the Leland Stanford University. 



W., U.S. National Herbarium, Washington, D.C. — If there is no in(Ueation of a herbarium, 

 the specimens are in A., the herbarium of the Arnold Arboretum (and mostly also in the other 

 herbaria). Other abbreviations are: m., male specimen. — f., female specimen in flower. — - 

 fr., fruiting specimen (im. fr. means with immature fruits). — st., sterile specimen. 



^ This refers to fully developed normal leaves towards the end of sterile branchlets or shoots. 

 The first (hnvermost) leaves of these branchlets and the leaves of the flower-bearing branchlets 

 (peduncles) are often very different and mostly much smaller. 



'^ *' Annotini'* is used here for the \vell-ri])ened branchlets of the previous season, while 

 "hornotini " is used for the shoots of this year. 



^ Very often the capsules are not ripe, but have been collected unripe and have opened in 

 drying. Hence they are frequently smaller or of a different shape. If not properly fertilized 

 the ovaries do not develop into normal capsules, but remain much smaller and look differently. 



