1883.] The Hibernacula of Herbs. 1107 
Involucral-bracts 2-seriate, equal, obtuse; achene small Gk), 
. T, mexicana, 
d. Achenial hairs long, slender; their branches long and circinately rolled 
downwards; heads 3 inch broad; pappus of very long bristles (ir), 
thickening at base; plant depressed, acaulescent, glabrous. 
leaves narrow-spathulate. . T. Watsoni. 
f- Achenial hairs simple or bifid, the lobes acute; heads mid-sized, peduncle 
mostly naked. 
Leaves cauline, linear, or the lowest sub-subspathulate, acute or acuminate ; 
involucral-bracts linear-lanceolate, 16. T. florifer. 
Leaves radical, spathulate, their limb mostly broad and short; heads on 
short scapes; involucral bracts somewhat broad-lanceolate. 
17. T, scapigera. 
THE HIBERNACULA OF HERBS. 
Jeme 
BY AUG. F. FOERSTE. 
F the fall of the year, as the weather grows colder, the produc- 
tion of the normal leaves of trees is suddenly checked. They 
wither and fall off. Instead of them we find a close, compact 
cluster of scales, and within these a number of young leaves and 
sometimes flower-buds. These scales are designed to protect the 
young leaves and flowers from the cold during winter; they are 
therefore called the hibernacula or winter quarters of the tender 
Parts. Towards. spring the growth of the inclosed leaves and 
buds is very rapid, so as to burst open their coverings and allow a 
Speedy development of the floral organs. Hence most trees pos- 
sessing scaly buds flower early in the spring of the year. 
t may not be as well known, however, that it is not at all un- 
common for the earlier flowering, perennial herbs to possess hiber- 
nacula, or winter buds, containing the flowers of the following 
year; and that many of them owe the power of early developing 
their flowers to this fact. On the study of a great variety of 
belonging to all classes of flowering plants, during the win- 
ter months, it became evident that such cases were by no means 
Tare. Such a study may reveal also many other interesting facts 
as the following pages will show. 
‘rennial herbs, on the approach of winter, die down to the 
of the ground. The stem still remaining beneath the 
“arth is called the subterranean stem, and furnishes the buds from 
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