4 ARISAEMA TRIPHYLLUM 
Whether or not these plants would bear flowers the following year 
cannot be determined with certainty; but the finding of an oc- 
casional plant in March or early April showing active tetrad di- 
visions indicates the probability that such plants pass the winter 
with the buds very immature. The wide variations just noted 
have been observed both in the greenhouse, where all the plants of 
a group have received identical treatment, and in the field. 
Of the accessory floral structures the spathe develops first, 
and shows the appearance of a miniature but otherwise perfect 
envelope (TEXT FIG. 2) before the reduction division of the pollen 
mother cells or the investment of the nucellus by the integuments. 
With the resumption of activity in the spring the spathe grows 
rapidly, as a leaf, and is mature before the flower breaks through 
the soil. The sterile club of the spadix appears as a small conical 
protuberance above the flower clusters when the individual anthers 
can first be recognized, and makes its chief growth after the 
spring development begins. Its mature form is not attained 
until the flowers are fully developed. 
As would be expected from the great difference in the time of 
development of the flower parts, there is much variation in the 
time of maturity of the inflorescence. If March be mild and warm, 
a few “Jacks” may be seen during the first week of April. Most 
of the plants are in full bloom during the last week of April and 
the first half of May. A few fresh flower clusters may be found 
during the first week of June. 
It has been observed that the first flowers to appear are 
staminate. All through the season the staminate spikes are found 
mature before the pistillate spikes of plants in the same group. 
Even more striking is the difference in time of maturity of flowers 
on mixed spikes. On the spikes where the oldest ovule shows a 
megaspore mother cell with a resting nucleus, anthers with com- 
pleted tetrads have been found. On older spikes anthers discharg- 
ing spores have been found with ovules showing tetrads of mega- 
spores or the germination of such. 
THE STAMINATE FLOWER AND MICROSPORE 
The staminate spike is 5-10 mm. long and its axis 2-4 mm. 
in thickness, being rather more slender than that of the pistillate 
