EXPLANATION OF THE PLATES. 
255 
Fig. 9. Amaranthus hypochondriacus. Amaranthidece . 
Pyxidium uncovered, and magnified, membranaceous. 
Fig. 10. Valves of the same, separated. 
Fig. 11 . Kernel of the same magnified; perisperm cen- 
tral; embryo peripherical, annular ; cotyledons semicylin- 
drical, incumbent; radicle threadlike, below. 
Fig. 1 2. Salsola decumbens. Chenopodece. Periphyllum 
magnified, containing the utriculus. 
Fig. 13. Perigonium of the same cut vertically, and 
magnified, to show the seed. 
Fig. 14. Embryo of the same, highly magnified ; thread- 
like, rolled in a ball, cotyledons very long, linear; radicle 
nearly cylindrical, placed horizontally in the uppermost part 
of the seed. 
Fig. 15. Carex vulpina. Cyperacece. Persistent spathel- 
lules cut longitudinally and magnified ; akenium pedicelled, 
enclosed in the spathellules. 
Fig. 16. Akenium of the same cut longitudinally and 
magnified; style persistent; embryo at the base of the 
seed. 
Fig. 17. Gomphrena globosa. Amaranthidece. Pyxidium 
cut longitudinally and magnified; st} T le persistent; seed 
single, inverted, hanging by the umbilical cord, proceeding 
from the bottom of the pyxidium. 
Fig. 18. Beta vulgaris. Chenopodece. Utriculus enclosed 
within the fleshy perigonium, and magnified. 
Fig. 19. The utriculus of the same cut transversely and 
magnified; embryo annular. 
Fig. 20. Thesium alpinum. Santalacece. Pericarpium 
magnified; crowned by the persistent perigonium. 
Fig. 21. The same cut transversely. 
Fig. 22. The seed of the same cut longitudinally and 
magnified ; embryo straight, central. 
Fig. 23. Embryo of the same, highly magnified. 
Fig. 24. Fraxinus excelsior. Fraxinece. Samara opened 
before it is ripe ; two-celled ; ovules four, hanging two side 
by side in each cell. 
Fig. 25. The ripe samara of the same; opened; having- 
only one seed, pendulous ; the others having perished. 
Fig. 26. Ulmus Americana. Utmacece. Samara with the 
cell opened ; seed pendent. 
