CHAPTER XI 
DIVISION OF TERRESTRIAL PLANTS ACCORDING TO 
THEIR LONGEVITY AND FREQUENCY OF SEEDING 
Division of Plants according to their Longevity. 
1. Annuals.—These plants live through one or part of 
one vegetative season and then perish, after providing for 
the continuance of the race by the production of seed— 
€.g., poppies, groundsel, chickweed. There are two kinds 
of annuals : 
(a) Those which germinate from seed in the spring, and 
perish towards the close of the vegetative season—summer- 
annuals—e.g., poppy. 
(6) Those which germinate from seed in the autumn, 
forming small plants with a few leaves, arranged on the 
rosette plan, close to the ground, and continue their 
growth in the following spring—autumn-annuals. They 
flower early, and perish before the hottest part of the 
summer sets in. Annuals belonging to this class must 
seed very freely because the fatality among the seedlings 
during the winter is very great. 
In both cases there is a season during which the plants 
are not seen at all. In the case of summer-annuals this 
season is the period of vegetative rest, winter ; in the case 
of autumn-annuals, which are vernal bloomers, it is the 
summer, when hot, dry conditions bring about a period 
physiologically unfavourable to the plants. The latter 
are found chiefly in dry steppe-regions, or in sandy and 
stony places which become very hot and dry in summer. 
They are not common in England, but a few are found 
on sand-dunes, a habitat specially remarked for summer 
drought—e.g., the vernal whitlow-grass (Draba verna), 
the early forget-me-not (Myosotis collina), and the small 
mouse-ear chickweed (Cerastiwm semidecandrum). 
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