166 



GEOLOGY OF LA SALLE COUNTY. 



Rolygfonum erectum, 117. Erect, 1-2 feet, yel- 

 lowish, leaves oblong-. 



P. Virg-inianiim. Smooth, 3-4 feet, sheaths hairy 

 and fringed, leaves ovate or ovate lanceolate, acute, 

 rounded at base, petioled. 



Saururus cernuus, 118. After Asarum. 



P. Marsh herbs, leaves cordate petioled, flower 

 white, frag^rant in nodding- spikes. 



Sassafras officinale, 118. Before Thynielaceae. 

 Tree 15-25 feet, twig's yellow g-reen, leaves ovate or 2 

 or 3 lobed, flowers green yellow, aromatic. Both sides 

 of Illinois, west of Lover's Leap. 



Smilax rotundifolium, 122. Leaves ovate or 

 round-ovate, cordate short, pointed, thickish, g-reen 

 both sides, stem more or less beset with black prickles. 



S. g-lauca. Prickles stout, leaves ovate. 



S. pseudo china. Smooth or few prickles, 

 leaves ovate cordate. 



Acorus calamus, 124. Sweet flag-, calamus, 

 Flowers on a spadix, yellow g-reen, no proper leaf, very 

 diflFerent from blue flag-, aromatic. 



Carex tribuloedes var. Cristata, 127. Spikes 

 almost g-lobular. 



Elecharis ovata, 125. Nearly round, 8-14 inches, 

 high. 



C. laxiflora var. latifolia, 127. Leaves ^ inch 

 broad or more, staminate spike nearly or quite sessile. 

 Panicum commulatus, 128. 

 P. scoparius, pubescens. 

 Phalaris aurundinacea, 129. 

 Sporobolos minas, 129. 

 Ag-rostis personans, 130. 



Koeleria cristata, 130. Before Eatonia. Spike- 

 lets in a dense, narrow spike-like panicle. Dry sands. 

 Eatonia Pennsylvanica, 130. 



