108 [164|.% ~ EXPLANATION OF THE PLATES. 
Prate VI. HORKELIA TRIDENTATA.--Paar 84. 
AN ENTIRE PLANT OF SIZE. 
An expanded flower and two buds; enlarged. 
The flower laid open; a little more enlarged. 
A petal; magnified. 
A stamen ; more magnified. 
The head of pistils. 
An achenium, with its persistent style. 
oR Ne 
Puare VII. WHIPPLEA MODESTA.— Pace 90. 
AN ENTIRE PLANT OF THE NATURAL SIZE. 
A searemae flower; moderately enlarged. 
A sepal ; 
A petal ; oth a little more enlarged. 
Front view 
Back view - the same; equally magnified. 
Pistil, transversely a ae more magnified. 
An ovule; more magni 
A flower, longtaally ded: considerably magnified. 
. Plan of the flower, 
22... 
Piate VIII. CORNUS SESSILIS.—Pace 94. 
A BRANCH OF THE NATURAL SIZE. 
Umbel of flowers and involucre. 
The involucre ; a nates 
An exterior leaf of 
Interior leaf of ea same. 
A separate flow 
The same, with ‘es of the petals — stamens removed to show the teeth of the calyx. 
The fruit. 
i 
Puate IX. HOFMEISTERIA PLURISETA.—Pace 96. 
A PLANT OF THE NATURAL SIZE. 
1. A separate flower; enlarged. 
2. The corolla of the same Jaid open; more magnified. 
3. A stamen ; still more magnified 
4. Two pale and a hair of the oder more magnifi 
5. An achenium, crowned with its pappus ; charms magnified. 
6. Involucre and receptacle ; moderately ma en 
Pirate X. ASTER BIGELOVI.--Pace 97. 
UPPER PORTION OF THE PLANT OF THE NATURAL SIZE. 
Fig. A ray flow 
. A branch of: the style from the same. 
A disk fi 
A separa ry pene from the 
. Style and its oe from a ta flower. 
. An achen 
7. A hair of oo pappus ; highly magnified. 
