LIST OF ILLUSTRATIONS. 
Facing page. 
Plate I. Map of part of the sand-hill region of Nebraska, illustrating the 
route of P. A. Rydberg in 1893........---.------------+--------5- I 
Il. Carduus plattensis Rydberg......-.-.------- 20-20-22 e eee eee eee 167 
III. Cardamine leibergit Holzinger.....----....----+----- +--+ +--+ 222s eee 212 
IV. Viola orbieulata Geyer ......---.------ +--+ 2-2 eee ee eee ee eee eee 214 
V. Coarana purpurea Coulter & Rose ....-.------ ---+ +++ + 2222-25 ee eee 297 
VI. Deanea nudicaulis Coulter & Rose .......------+- +--+ +--+ ---- 227+ 298 
VII. Neoqoezia gracilipes Hemsley........--.------ +--+ 0-222 eee ce reer 305 
VIII. Neogoczia minor Hemsley -. .------------- Lea eee eee ce eens cece ees 306 
IX. Neonelsonia ovata Coulter & Rose.....----...---- - 222 ee ee eee eee 307 
X. Osmorrhiza mexicana Grisel)...........-.2---- 0-0-0 eee eee eee eee 307 
XI. Mimosa spirocarpa Rose ......-------- +--+ 22-20-22 tre crete 316 
XII. Ligusticum verticillatum (Hook.) Coulter & Rose...-..-------------- 320 
XIII. Ligusticum eastwoode Coulter & Rose ....-.------ +--+ +25 222025 e+ > 320 
XIV. Velaa glauca Coulter & Rose ......-..------ +--+ +++ - 2 ere ee eee e cee 321 
XV. Thurovia triflora Rose ......---. ---- 2-22 eee eee eer eee 321 
XVI. Tradescantia brevifolia (Torr.) Rose ........-..----. -----2 2-22 ee eee 323 
XVII. Map of the Black Hills........-...---.---- +--+ ---- ee ee cere eee eee I 
XVID. Aquilegia brevistyla Wook .....----- +--+ +. 02-222 225 eee e ee cece ce 481 
XIX. Aquilegia sarimontana Rydberg .....------+---- +--+ 222225 e erro 482 
XX. Poa pseudopratensis Scribner & Rydherg ..-------------+--+-+------ 532 
XXT. Crepis occidentalis Nutt .....--------- 2-22 222-2 erect eee eee 560 
XXII. Crepis monticola Coville ......-.---------+ +--+ 22+ peer rete eee nee 562 
XXII]. Crepis subacaulis (Kellogg) Coville... ....--.------------+----5-0- . 662 
XXIV. Crepis scopulorum Coville ........2-..---- +22 2-2-2222 rere 563 
XXV. Crepis rostrata Coville .....2-..------ 02-2 +--+ +222 eee eee eee 564 
XXVI. Crepis barbigera Leiberg .-...---.----- +--+ ---- +222 errr tere 565 
XXVIII. Leibergia orogenivides Coulter & Rose ...--..-.--- +--+ +22 22225 -- >> 5TO 
XXVIII. Roseanthus albiflorus Cogniaux ......-- ----- 222-22 eee eee eee eee 577 
VIL 
