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FIGWORT FAMILY 



on the floor of Yosemite Valley, the stems are tall, often 

 2 ft. or more high, and with 3 to 5 dense, floral whorls well 



Pentstemon confertus. — The inflorescence of the common form and an 

 entire plant of the Alpine form. Both figures are natural size. 



separated on the central shaft. At higher altitudes, as on 

 Mt. Hoffmann, at 8500 ft., the plants are 7 or 8 in. high and 

 the flower-clusters are reduced to 2 or 3. Exceedingly dwarf 

 plants, only 2 or 3 in. high, and with flowers all in a single 

 terminal cluster, is encountered above timber-line on Mt. 

 Dana and Mt. Lyell, where it grows in moist soil close up 

 to banks of perpetual snow. In this Alpine form, some- 

 times known as P. geniculatus Greene, the root-system is 

 longer than all of the rest of the plant. Near Mt. Whitney 

 we found a form 1 ft. high and with 3 whorls of flowers 

 neighboring with plants only 3 in. high and with a single 

 whorl. This variation, all within a small area, was apparently 

 due to the light relation, the tall ones growing in the shade, 

 the shortest ones only in the open meadow, while all inter- 

 mediate forms were found in partial shade. 



5. P. laetus Gray. Plant a foot or two high, with slender 



