402 DESCRIPTION OF PLATES. 



PLATE VI. 



Aplopappus cervinus, Watson.-Fig. 1. Branch natural size. Fig. 2. Inner scale of involucre. 

 Fig. 3. Outer scale of involucre. Fig. 4. Disk-flower. Fig. 5. Style and stigma. Fig. 6. Anther. All 

 enlarged except the branch. 



PLATE VII. 



A. Townsendia Rothrockii, Gray.— Natural size. Fig. 1. Inner scale of involucre. Fig. 2. 

 Kay-flower. Fig. 3. Ray-flower, style, and stigma. Fig. 4. Portion of pappus of ray-flower, enlarged 

 25 times. Fig. 5. Disk-flower. Fig. 6. Cross-section of achenium. Fig. 7. Style and stigma of disk- 

 flower. Fig. 8. Bristle from ray-flower pappus. All 10 diameters, except when otherwise stated. 



B. Aster Coloradoensis, Gray.— Natural size. Fig. 9. Ray-flower. Fig. 10. Ray-flower style 

 and stigma. Fig. 11. Disk-flower. Fig. 12. Disk-flower style and stigma. Fig. 13. Achenium and 

 pappus of disk-flower. Enlarged about 10 times. 



PLATE VEIL 



Actinomeris Wrighth, Gray.— Branches natural size. Fig. 1. Ray-flower. Fig. 2. Disk-flower 

 and subtending chaff. Fig. 3. Disk-corolla, with style protruding. (Figs. 1, 2, and 3 enlarged about 

 4 times.) Fig. 4. Style and stigma, 10 diameters. Fig. 5. Mature achenium, enlarged 15 times. 



PLATE IX. 



Wtethia Arizonica, Gray. — Branch natural size. Fig. 1. Section through receptacle, showing 

 ray-flower and disk-flower in position, the latter subtended by its chaff; somewhat enlarged. Fig. 2. 

 Chaff of disk-flower. Fig. 3. Disk-flower. Fig. 4. Style and stigma of disk-flower. Fig. 5. Mature 

 achenium of disk-flower. Fig. 6. Style and stigma of ray-flower. Fig. 7. Mature achenium of ray- 

 flower. All 10 diameters, unless otherwise stated. 



PLATE X. 



Hemtzonia Wheeleri, Gray. — Natural size. Fig. 1. Vertical section through receptacle, show- 

 ing ray- and disk-flowers in position. Fig. 2. Ray-flower, with its achenium enclosed by scale of invo- 

 lucre. Fig. 3. Chaff of disk. Fig. 4. Disk-flower with abortive ovary. Fig. 5. Top view of receptacle, 

 showing also scales of the involucre. Fig. 6. Scale of involucre enclosing ray-achenium. Fig. 7. 

 Mature ray-flower achenium. 



PLATE XI. 



Laphamia megalocephala, Watson. — Fig. 1. Branch natural size. Fig. 2. Single flower. Fig. 



3. Style and stigma. Fig. 4. — . Fig. 5. Stamen. All enlarged about 10 times. 



PLATE XH. 



Leucampyx Newberryi, Gray. — Natural size. Fig. 1. Vertical section through the receptacle, 

 showing ray- and disk-flowers ; also involucral scale and embracing chaff. Fig. 2. Single scale of invo- 

 lucre. Fig. 3. Ray-flower. Fig. 4. Chaff of the receptacle. Fig. 5. Disk-flower. Fig. 6. Style and 

 stigma of disk-flower. All except the branch enlarged about 7 times. 



PLATE XUI. 



Artemisia Rothrockii, Gray.— Natural Bize. Fig. 1. Head of flowers. Fig. 2. Section through 

 the same. Both enlarged about 12 times. Fig. 3. A single flower. Fig. 4. Style and stigma. 



PLATE XIV. 



Pyrrhopappus Rothrockii, Gray.— Natural size. Fig. 1. Flower, enlarged 5 times. Kg. 2. 

 Style and stigma, enlarged about 15 times. Fig. 3. Young head closed, enlarged about 3 times. Fig. 



4. Achenium and pappus, enlarged about 5 diameters. Fig. 5. Involucre refiexed, showing markings on 

 the convex receptacle, enlarged about 4 times. 



