19211 SCHNEIDER, NOTES ON AMERICAN WILLOWS, XII. 97 



Ramuli floriferi crassi distincte pubescentes vel tomentosi; amenta 



4-6.5 : 1-1.3 cm. magna, sessilia, basi bracteolis paucis lanceolatis 



laxe pilosis minute denticulatis obsita .... 58. S. missouricnsis. 



Ramuli floriferi glabri vel amenta minora. Confer species sequen- 



tes: 56. S. ligulifolia, 56. S. cordata, 59. S. mackenzieana, 61. S. 



monochroma, 63. S. pseudocordata, et 62. S. myrtillifolia. 



Amenta pedunculo distincto foliolato suffulta, coetanea vel satis serotina. 



(Confer etiam species Sect. Cordatae). 



Ramuli floriferi plusminusve et praesertim novelli satis dense tomentosi vel 



villosi. 

 Foliola pedunculorum circumcirca dense minute glanduloso-serrata vel 



denticulata . . . . 68. S. adcnophylla. 



Foliola pedunculorum integerrima vel tantum parce (in S. commutata 

 interdum densius) denticulata. 

 Bracteae oblongo-lanceolatae, satis flavo-brunneae; folia utrinque 



concoloria et stomatifera 69. S. commutata 



Bracteae obovales vel obovato-oblongae, supra medium fuscae; folia 

 subtus discoloria, superne haud stomatifera. 

 Pedunculi distincte foliolati, ad 2 cm. longi; foliola ut videtur semper 



integerrima (species rara alaskana) 77. S. amphfolia. 



Pedunculi subnulli vel foliola parva margine plusminusve glandu- 

 loso-denticulata. Confer 65. S. Barclayi et 78. S. Hookerianam. 

 Ramuli floriferi (et saepissime etiam novelli) glabri. 



Foliola pedunculorum circumcirca satis dense m'nute glanduloso-den- 

 ticulata; glanduhi brevis, crassa, fere quadrato-globosa; bracteae satis 



brunneae vel apice rubescentes 72. S. pyrifolia. 



Foliola pedunculorum integerrima vel sparse denticulata et glandula 

 saepissime magis elongata. 

 Amenta parva pedunculo excluso vix ad 1.5:0.7 cm. magna; _ foliola 

 foliaque novella subtus dense adpresse sericea; antherae minimae, 



globosae, ? violaceae 114. S. argyrocarpa. 



Amenta majora; foliola foliaque plusminusve glabra vel antherae diver- 



sae. 



Folia novella (et saepe matura) laxe vel densius (praesertim superne) 

 pubescentia (Confer etiam 78b. S. Hookerianam var. laurifoliam)^ 



65. S. Barclayi. 



Folia etiam novella glaberrima vel citissime glabra, interdum subtus 



ad costam pilosula. 

 Bracteae satis dense sericeae; antherae distincte flavae; amenta 

 densiflora tantum foliolis parvis plusminusve denticulatis suffulta 



68. S. glaucophylloides. 



Bracteae saepissime tantum parce sericeae; antherae (?an semper) 

 purpureae; amenta laxiflora foliolis quam folia paullo minoribus 

 integerrimis suffulta 87. S. pedicellarls 



II. CLAVIS SPECIERUM SECUNDUM SPECIMINA FEMINEA. 1 



A. Bracteae florum stramineae et sub fructi non persistentes (B, vide p. 99) 



a. Flores glandulis duobus (ventrali et dorsali) instructi 



Amenta serotina, pedunculis satis normaliter foliatis suffulta; folia glabra (forma 

 rara brasiliensis) lc. S. Humboldtiana var. Martiana 



Amenta coetanea satis breviter pedunculata; folia utrinque adpresse sericea 

 (forma rara e Nevada et California) 18c. S. cxigua var. nevadensis. 



b. Flores normaliter glandula unica ventrali instructi. 2 

 Amenta saepissime serotina/ interdum in codem pedunculo vel ramulo laterali 



1 Of the Mexican species 115. S. cana and 98. S. oxylepis the female plants are still 



unknown . 



2 As I have pointed out in Bot. Gaz. LXV, 15 (1918) the glands of the species of 

 Sect. Bonplnndinnae as well of some of Sect. Pentandrae subsect. Lucidae sometimes 

 have a somewhat cup-shaped ventral ^land but the dorsal gland is usually wanting. 



3 Under certain climatic conditions the aments may develop rather suddenly with 



