146 IOWA ACADEMY OF SCIENCES. 



willow. la its general character it is probably the least vari- 

 able of any of our common species. The leaves vary in length 

 from three to five and even six inches, and in width from two 

 to six lines, although three and one-half is the average. The 

 single leaf which subtends a young twig is usually much 

 broader than the other leaves. They are normally silky pubes- 

 cent when young, and frequently retain this pubescence 

 when mature, especially in northern regions and the Rocky 

 mountains. A specimen of mature foliage collected M Arm- 

 strong, Emmet county, in 1895, by Professor Shimek, is 

 peculiar in that the leaves are nearly all small, short, stiff, 

 and densely silky. A few such leaves are, however, not 

 uncommon on the basal portions of otherwise typical twigs. 



This willow has a longer flowering period than any other 

 species io Iowa. It extends Irom about April 25th to June 15th 

 normally. A staminate specimen from Lee county, collected 

 August 1, 1895 (Bartsch), shows the aments just expanding. 

 Fruit is frequently collected late in July and once by Professor 

 Hitchcock in September. Two or three young aments are 

 generally developed near the base of each one first produced. 

 The pistillate aments vary in length from one to two and one- 

 half inches, with an average of one and one-fourth, and are 

 quite loose in fruit. The staminate aments average one inch 

 in length. The anthers were unusually long ia some speci- 

 mens. The capsules are densely silvery silky when young but 

 often become entirely glabrous when mature. They are short- 

 pedicelled and have an average length of three and one-half 

 lines. The scales are lanceolate, ovate, or sometimes obovate, 

 densely villous. 



Rock Rapids, Lyoa Ox 2, Shimeh, S. U. I.; Spirit Lake, Dickinson Co. 4, Shimek, S. 

 U. 7 ; Armstrong, Emmet Oo. 5, Cratty, Herb. (3 spec), Shimek, S. 17. I.; Iowa Lake, 

 Emmet Co. 6, Shimek, S. U. I ; Hackberry Grove, Cerro Gordo Oo. 13, Shimek, S. U. 1.; 

 Charles City, Floyd Oo. 14, Arthur (Engelm Herb. Mo. Bot. Oard.) ; Fayette, Fayette Oo. 

 18, Fink, Herb. (2 spec); Fort Dodge. Webster Oo. 20, Shimek, S. U. I.; Delaware Oo. 23, 

 Cameron, S. U. I ; Story City, Story Oo. 26, Pammel and Beyer {No. 1175) ; Ames, Story Co. 

 28, Bessey {4 spec ) Reynolds, Hitchcock, Fay, McKinley, Sample, Ball and Sample (No. 1176) ; 

 Cambridge, Story Co. 89, Sample; Tama Co. 31, Si7-rine; High Bridge, Dallas Co. 35, 

 Shimek, S. U. I.; Johnson Co. 36, Shimek (2 spec.) S. U. I.; Davenport. 39, Shimek (2 spee.) 

 S. 17. 7 ; Blue Grass, Scott Co. 40, Barnes A Afiiier (No. 3); Muscatine 41, Reppert, Herb. 

 (No. 657), Shimek, S. U. I. Ball (No. 1174); Carson. Pottawattamie Oo. i2,Cameron,S, U. L, 

 Mt. Pleasant, Henry Co. 44, Mills, Herb.; Skunk R. Valley, Lee Oo. 45, Bartsch, S. U. 1.; 

 Keokuk. 46, Shimek, S. U. I. 



