8 JOURNAL OF THE ARNOLD ARBORETUM [vol. i 



see it is hardly possible to separate any other forms but the two following. 

 As to S. ambigua Pursh I can only say that it deserves its name until we 



find a type specimen. 



2b. S. nigra var. altissima Sargent in Trees & Shrubs, ii. 216 (1913). 

 ? Salix spec, Robin, Voy. Louisiana, iii. 521 (1807). — ? S. denudata Rafin- 

 esque, Florul, Ludovic. 116 (1817). — As the varietal name indicates this wil- 

 low becomes the tallest American Salix growing u]> to the height of 40 m. 

 The type was collected near Fulton on the Red River, Hempstead County, 

 Arkansas, May 20, 1909, by the well-known collector B. F. Bush (No. 5654, 

 fr.; A.). Except in its size it differs from the type only in the more pubes- 

 cent young shoots, leaves and especially the petioles which are almost 

 barbate-ton:ientose above and on the average are com]>aratively longer, and 

 in the shape of its leaves which as a whole are more acute at the base thus 

 resembling var. Lindheuncrii. Besides this var. altissima flowers a little 

 later than the tj7>e where botli grow together. I have seen specimens from 

 Arkansas (Ilcmpstead County), Louisiana (Caddo, Winn, Richland, 

 Rai)ides, West Feliciana, New Orleans, St. T^andry, Jefferson, Lafayette and 

 Calcasieu Parishes), and from eastern Texas (Harrison, San Augustine, 

 Polk, Walker, Harris, Houston, and Jefferson Counties) but some of the 

 Texan forms need further study and may jjartly be referable to var. Lind- 

 heimerii. Sargent suggested that S, manjinata Wimmer might be identical 

 with var. altissima, but Wimmer's form belongs to .S. lojigipcs venulosa, 

 S. denudata Rafinesque mentioned in the sjmonymy is an obscure species 

 very badly described, but it seems to be referable to var. altissima. 



2c. S. nigra var. Lindheimerii Schneider in Bot. Gaz. lxv. 9 (1918), — I 

 have (1. c.) already dealt with this interesting variety which in some re- 

 spects seems to form a connecting link between S. nigra and its southern 

 representative, S. Humholdtiana (var. stipulacea), and I have enumerated 

 the sx)ecimens examined from Mexico. In the L'nited States It is found in 

 the eastern part of central Texas and in southeastern Texas wlierc I have 

 seen it from the following counties: Grayson, Dallas, Tarrant, McLennan, 

 Bell, Gillespie, Kendall, Comal, Bexar, Wilson, Calvado, Harris, Polk, 



Brazoria, Wharton, Matagorda, Victoria, Atascosa, Refugio; a si)ecimen 

 from Caddo Countv, Ix>uisiana, is rather intermediate between var. altis- 

 sima and var. Lindheimerii, and a sterile one from western Texas, Jeff 

 Davis County (near Fort Davis, D. M. Andrews, No. 77; A.) belongs 

 probaljly to those forms from Texas whicli I am unable to distinguish from 

 ty})ical S. nigra.^ The var. Lindheimerii may also occur somewhere in 

 southern Oklahoma along the Red River, and it seems to me to be con- 

 nected by intermediates in the north with typical *S. nigra, and more to the 

 east with var. altissima, while in Mexico it comes very near S. ITumboldti- 

 ana as I have previously stated. 



^ S. n/jra Coulter in Contrlb. U.S. Nat. Herb. ii. 419 (1S1)2\ pr()l)ably belongs partly to var. 

 Lindheimerii, and his var. WriglUii seems also to represent a form of S. nigra and not the true 

 S. Wrightii, A sterile specimen collected by C. 11. Ball on the Hear Creek, 14 mi. northwest 

 of Junction, Kimble County, August 25, 1909 (No. 1537; O.) has very short petioles, and looks 

 much like typical S. nigra. 



