DESCRIPTION OF PLATES. 403 



PLATE XV. 



CttffiTADELPHA Wheeleri, Gray. — Branch natural size. Fig. 1. Involucre, enlarged about 4 

 times. Fig. 2. Single flower, about 5 diameters. Fig. 3. Style and opened anther-tube, enlarged 10 

 times. Fig. 4. Mature achenium and pappus, enlarged about 4 diameters. Fig. 5. A branching bristle 

 of the pappus, enlarged about 10 diameters. 



PLATE XVI. 



Palmerella debilis, var. serrata, Gray. — Natural size. Fig. 1. Single flower. Fig. 2. Flower, 

 split open, showing the adnate filaments and united anthers, two of which are bristle-tufted at the 

 apex. Fig. 3. Vertical section through flower. Fig. 4. Cross-section through ovary, showing ovules 

 on the central placenta. 



PLATE XVLT. 



Hedeoma HY8SOPIFOLIA, Gray. — Natural size. Fig. 1. Flower. Fig. 2. Vertical section through 

 flower. Fig. 3. Calyx. Fig. 4. Corolla, opened longitudinally, showing nutlets, style, two perfect 

 and two rudimentary stamens. All enlarged 5 diameters. 



PLATE XVIH. 



Nama Rothrockh, Gray. — Natural size. Fig. 1. Single flower. Fig. 2. Corolla, laid open, show- 

 ing stamens. Fig. 3. Calyx, enclosing pistil. Fig. 4. Vertical section through ovary. Fig. 5. Cross- 

 section through ovary. Fig. 6. Seed. All enlarged. 



PLATE XIX. 



A. Gilia debilis, Watson.— Natural size. Fig. 1. Flower. Fig. 2. Corolla, split open. En- 

 larged about 5 diameters. 



B. Gilia demissa, Gray. — Natural size. 



PLATE XX. 



Convolvulus longipes, Watson.— Fig. 1. Natural size. Fig. 2. Pistil. Fig. 3. Cross-section 

 of ovary. Fig. 4. Stamen. Figs. 2, 3, and 4 enlarged. 



PLATE XXI. 



Halenia Eothkockh, Gray.— Natural size. Fig. 1. Flower, enlarged about 5 diameters. Fig. 

 2. Cross-section of capsule, enlarged about 5 diameters. Fig. 3. Vertical section through flower, 

 enlarged about 10 diameters. 



PLATE XXII. 



Fraxinus coriacea, Watson. — Fruiting branch, natural size. 



PLATE XXIII. 



Abronia villosa, Watson. — Fig. 1. Branch, natural size. Fig. 2. Flower laid open, enlarged 

 about 5 diameters. Fig. 3. Cross-section of fruit. 



PLATE XXrV. 



Atriplex Wolfii, Watson.— Natural size. Fig. 1. Staminate flower, enlarged 12-15 diameters. 

 Fig. 2. Pistillate flower, enlarged about 10 diameters. Fig. 3. Pistil, enlarged about 10 diameters. 

 Fig. 4. Vertical section through Fig. 2. Figs. 5. Mature fruit; 6. Vertical section of the same; 7. 

 Its annular embryo, all enlarged about 10 times. 



