82 STUDIES IN THE VEGETATION OF THE STATE 



respectively, continue in diminishing numbers in the higher 

 prairies, the low prairies, and the meadows, and pass out 

 entirely with the advent of the serotinal period. The grayish- 

 white plants of Amorpha canescens are still conspicuous ob- 

 jects on ridges, though long past anthesis. They give the 

 floral covering a "ragged" appearance. Ceanothiis ovatus 

 is represented now by a mass of low, leafy bushes, abundant 

 on ridges and scattered here and there on the higher slopes. 

 The white flowers of Erigeron ramosus and the bright yel- 

 low of Coreopsis palmata have disappeared entirely from 

 the formation, and their places have been taken by the taller 

 and more prominent Euphorbia corollata, the flat-topped 

 flower clusters of which are conspicuous on every ridge and 

 slope. Others that lend coloring to the aspect are Laciniaria 

 squarrosa on ridges, SoUdago rupestris in high and low prai- 

 ries, ^ilphium laciniatmn in low prairies and meadows, 8. 

 integrifolium and Vernonia gigantea in low meadows, and 

 Cassia chamaecrista in locations heretofore given. 



Euphorbia corollata occurs, with two exceptions, in every 

 quadrat from II-XXII. It averages 50 individuals to the 

 five-meter square, though in several instances more than 

 twice that number have been counted. E. corollata is prom- 

 inent in this formation, not alone on account of its size, over- 

 topping as it does all other species within its patch, but also 

 because of its advantageous distribution and gregario-copi- 

 ous disposition. The strict stems are about one meter high, 

 clothed with bright green leaves and crowned with large, 

 white, flat-topped umbels. This milk spurge is an aianthous 

 bloomer; its flowers appear about the middle of June, in- 

 creasing in numbers until August 1, after Avhich time they 

 gradually diminish. The stems and leaves are not eaten by 

 stock on account of the milky juice they contain, a property 

 which gives the plant a decided advantage in pastures. The 

 plant is perennial by means of long rootstalks. 



Laciniaria squarrosa is a xerophyte of the crest of Great 

 ridge, occurring rather infrequently. It ranges from 6-55 



