20 MISSOURI BOTANICAL GARDEN BULLETIN 
tributed a great deal to the present enviable position of the 
peony. The gradual evolution into the highly colored, 
fragrant, double flower of to-day has come about through 
the natural tendency towards variation aided by the change 
of climate, environment, and ease of hybridization. 
Because of the extensive variation the peony flowers have 
been classified into seven types — single, Japanese, anemone, 
semi-double, crown, bomb, and rose. (1) Single peonies are 
composed of a ring of broad guard petals surrounding a 
mass of stamens and carpels. (2) The Japanese type shows 
the first indication of doubling. The filaments of the sta- 
mens have broadened, while the guard petals have remained 
the same. (3) The anemone presents the next develop- 
ment in doubling. The filaments have been converted into 
narrow petals, the anthers disappearing completely. (4) The 
semi-double is not really a step in advance of the anemone, 
as a few stamens still remain, though those which have 
changed into petals have begun to resemble the guard petals 
very strongly. (5) The crown type exemplifies the change 
of carpels into petals which are slender and reflexed. (6) In 
the bomb type we have the combination of doubling of 
both the stamens and the carpels, but the guard petals are still 
slightly different. (7) The fully double type is the rose 
where the petals are evenly arranged, very often indis- 
tinguishable from the guard petals. It is to be noted in 
this connection that extensive studies have revealed that 
fragrance increases with each successive type of doubling. 
The single peonies often possess a disagreeable odor, while 
the rose varieties are extremely fragrant. _ 
The one criticism usually voiced against the peony is the 
short duration of the bloom. This is a serious drawback, 
but the season may be prolonged six weeks or more by the 
use of a number of different species. P. tenuifolia is the 
first to bloom in the spring, followed by P. Witmanniana 
hybrids in May, and a little later by P. officinalis. Early in 
June the shrubby P. Moutan makes its debut with a wonder- 
ful mass of large flowers. It is closely followed by another 
shrubby form, P. lutea—a somewhat rare and recent intro- 
duction with large golden yellow flowers. The last to bloom 
are the numerous varieties of early, midseason, and late 
types of P. albiflora. 
From a cultural viewpoint the Paeonia ( Ranunculaceae) 
may be classified under two heads—the herbaceous and the 
tree, the herbaceous kinds composing by far the larger group. 
The propagation of herbaceous peonies is comparatively a 
simple process. Seeds may be sown or the fleshy rootstocks 
