THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. V, No. II] APRIL, 1910. 



Whole Skkies 

 Vol. XV, No. 11 



HISTOLOGY OF TOWNSENDIA EXSCAPA AND 

 LESQUERELLA SPATHULATA. 



bY LILIAN BUNTON. 

 Plates XXXVIII to XLV. 



''pWO excellent representatives of xerophytic vegetation, 

 ^ Toumsendia exscapa and LesqueveUa spatludata, were col- 

 lected in Gove county, Kansas, at an elevation of 2700 feet. 

 These plants are not common throughout this district and are 

 limited to certain localities. Toivnsimdia was found growing in 

 draws in the immediate vicinity of the town of Gove and also 

 on the flat, open prairie around "Castle Rock," about twenty- 

 five miles southeast of Gove, and in the vicinity of a group of 

 rocks known as the "Pyramids," thirty miles southwest. 



A general idea of the appearance of the vegetation of this 

 district may be derived from figure 1. My examples of Toivn- 

 sendia, therefore, were growing on the flat, open prairie as well 

 as in the draws, occurring not in clumps or patches, but as 

 isolated individuals within three or four feet of one another. 

 The plants on the open prairie show a more luxuriant growth 

 than those in the draws. 



The specimens of LesqueveUa were collected about twelve 

 miles southwest of the town of Gove on a rocky, clay bluff". 

 This plant, unlike Toiimsendia, was found growing not as iso- 

 lated individuals but in rather large colonies. 



Of all the ecological factors influencing the structure, habit 

 and distribution of plants the most potent is the water supply. 

 In Gove county the total precipitation for the year 1904 was 

 18.10 inches ; the greatest monthly precipitation was 4.13 inches, 

 in May ; the least monthly precipitation was inches in Febru- 

 ary and November, The total snowfall for the year was 5.5 



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