EXPLANATION OF THE PLATES 
Plate I. CEOSSOSOMA CALIFORNICA. — Page 63. 
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A BRANCH OF TIIE NATURAL SIZE. 
1. A branch with the leaves more fully developed, and the carpels half mature. 
2. Plan of the flower. 
3. A sepal. 
4. A petal. 
5 and 6. Front and back views of a stamen. 
7. A flower, longitudinally divided, to show the insertion of the stamens; all the figures moderately and equally 
enlarged. 
8. Transverse section of an ovary ; more enlarged. 
9. An ovule ; considerably magnified. 
Plate II. VIOLA SHELTONII.— Page 67. 
AN ENTIRE PLANT OE TIIE NATURAL SIZE. 
1. Three of the petals ; enlarged. 
2-4. Different views of a stamen. 
5. An anther divided transversely. 
6. The pistil; all the figures magnified. 
Plate III. THAMNOSMA MONTANUM.— Pace 73. 
TWO BRANCHES OF TIIE NATURAL SIZE—ONE IN FLOWER, THE OTHER IN FRUIT. 
1. Plan of the flower. 
2. A separate flower ; moderately enlarged. 
3. The same, with the calyx and petals removed. 
4. Immature fruit, showing the gynophore or prolongation of the glandular disk. 
5. Ovary, with one of the carpels longitudinally divided ; and, 
6. The same transversely divided ; magnified. 
7. An ovule ; more magnified. 
8. The fruit; enlarged. 
9. Seed, longitudinally divided ; magnified. 
Plate IV. HOSACK1A INCAN A.— Page 79. 
A TLANT OF THE NATURAL SIZE. 
1. The banner, a wing, and one of the keel-petals ; considerably magnified. 
2. Stamineal tube, laid open ; equally magnified. 
3. The pistil, longitudinally divided ; also equally magnified. 
4. An ovule ; highly magnified. 
Plate V. SPIRAEA MILLEFOLIUM.— Page 83. 
UPPER PART OF TIIE PLANT OF TIIE NATURAL SIZE. 
1. Plan of the flower. 
2. A petal; magnified. 
3. A stamen; equally magnified. 
4. Fructiferous calyx ; also equally magnified. 
5. A separate carpel. 
