1919] SCHNEIDER, NOTES ON AMERICAN WILLOWS. V 5 



Sect. I, Nigrae Loudon. — Sect. Anstrales Andersson in Ofv. Svensk. 

 Vetensk. Akad. Forh. xv. 114 (1858), ex parte, — Sect. Austro-americanae 

 sive sect. Ilumboldtianae Andersson in Svensk. Vetensk. Akad. Handl. vi. 

 15 (Mon. Salic.) (1867), ex parte. — -For further information see Schneider 

 in Bot. Gaz. lxv. 5 (1918). It may be mentioned that in a certain form 

 of S. nigra which will be discussed later the upper epidermis of the leaves 

 contains relatively few or no stomata at all. 



1. S- Humboldtiana Willdenow. — See Schneider, I. c. 6. — As I have 



stated, tliis species in its typical form is confined to South America. 



lb. S. Humboldtiana var. stipulacea (Martens & Galeotti) Schneider. 



See Schneider, 1. c. 7 (1918). — This variety represents the type In Central 

 America and Mexico but does not reach the southern border of the United 

 States. 



Ic. S. Humboldtiana var. Martiana (Leybold) Andersson. — See Schnei- 

 der, 1. c. 8 (1918). — * A badly understood form which seems to be confined 

 to certain parts of Brazil and Colombia. 



2. S. nigra Marshall, Arbust. Am. 139 (1785). — Muhlenberg in Neue 

 Schrift. Ges. Nat, Fr. Berlin, iv, 237, t. 6, fig. 5 (1803). — Michaux f., 

 Hist. Arb. Am. iii. 324, t. 5, fig. 1 (1813); N. Am. Sylva, iii. 78, t.l25, fig, 

 1 (1819). — Pursh, Fl. Am. Sept. m. 614 (1814). — Hooker, FL Bor,- 

 Am. II. 148 (1839). — Barratt, Salic. Am. no. 20 (1840). — Carey in Gray, 

 Man. 429 (1848), — Andersson In Svensk. Vetensk. Akad, Handl. vi. 19, 

 t. 2, fig. 15 (Monog. Salic.) (18G7), ex parte; in De Candolle, Prodr.xvi.^ 200 

 (1868), ex parte. — Ncwhall, Trees N.E. Am. 72, fig. 36 (1890), — Bebb 

 apud Watson & Coulter, Gray Man. ed. 6, 480 (1890), excl. var. Wardii, 

 Sargent, Sllva X. Am. ix, 103, t. 462 (1896), excl. syn. ex parte; Man. 

 Trees N, Am. 168, fig. 140 (1905), pro parte max. — Glatfelter in Trans. 

 Acad. Sci. St. Louis, vi. 427, t. 1, figs. 5-7, 10 (1894). — Britton & Brown, 

 111. FL I. 494, fig. 1173 (1896). — Sudworth in Bull. U.S. Dept. Agric. 

 Div. For. XIV. 118 (Nomencl. Arb. FL) (1897), ex parte. — Ball in Proc. 

 Iowa Acad. Sci. vii, 143 (1900); in Elys. Mar. iii. 19 (1910). — Mohr in 

 Contrib. U.S. Nat. Herb. vi. 465 (PL Life Ala.) (1901). — Small, Fl. S.E, 

 States, 341 (1903), ex parte. — Schneider, 111. Handb. Laubh. i. 32, figs, 

 lla-b, 12a (1904). — Hough, Handb. Trees, 78, figs. 91-92 (1907), pro parte 

 max. — Robinson &Fernald, Gray's Man, 320, fig. 640 (1908). — Britton 

 & Shafer, N. Am. Trees, 183, fig. 184 (1908), ex parte et excl. syn. — 

 Small, Shrubs Florida, 9 (1913). — Rydberg, FL Rocky Mts. 191 (1917). — 

 S. pentandra AValtcr, FL Car. 243 (1788). ^S. fiavo-virens Hornemann, 

 Cat, Hort. Hafn. Suppl. ii. 11, ex Willdenow, Berl. Baumz. ed. 2, 426 

 (1811), pro syn. S. nigrae. — S. Ugusirina Michaux f.. Hist. Arb. Am. iii. 

 326, t. 5, fig. 2 (1813); N. Am. Sylva, iii. 80, t. 125, fig. 2 (1819). — S. 

 falcata Pursh, FL Am. Sept. ii. 614 (1814). — Hooker, FL Bor,-Am. ii. 149 

 (1839). — Forbes, Salict. Woburn. 279, t. 148 (1829). — S. Houstoniana 

 Pursh, FL Am, Sept. ii, 614 (1814), ex parte. — Forbes, Salict. Woburn. 



