PLANT DESCRIPTION 229 
rosette the edges of which touch the ground, thus 
enclosing a space under a dome-like roof, which throws 
off the rain to soak through the shingle to the lone 
tap-root. The air enclosed within the space protects 
the plant against the extremes of heat and cold that 
prevail on the mountains that form its home; for 
air, being a bad conductor of heat, keeps the under 
sides of the leaves cool during the heat of the day, 
and warm through the intense cold of the night. The 
flowers have short stems and are densely crowded 
together. 
COMMON CRUCIFERS. 
1. Stocks are grown for their flowers. The night- 
scented stock is pollinated by night-flying moths. 
2. Watercress is common in ponds and streams. 
3. Cabbage are cultivated for their leaves, cauli- 
flower and broccoli for their inflorescence buds, 
Brussels sprouts for the axillary leaf buds, turnips 
and radishes for their roots, mustard for its seedlings. 
4, Shepherd’s Purse is a common weed in which the 
fruit is a silicula or short siliqua (Fig. 127). 
5. Honesty is a garden plant grown for its silvery 
oval silicule. 
6. Candytuft is another common garden flower. 
LEGUMINOS.2%. 
There are three main branches of the Leguminosa, 
two of which, the Mimosacez (introduced) to which 
the wattles belong, and the Papilionacee (both 
native and introduced) (L. papilio, a butterfly) which 
comprises all the bean-like plants, are common 
throughout New Zealand; the Garden Pea (Pisum 
sativum Figs. 128-129) is a characteristic plant of the 
sub-order Papilionacee. 
Habit. A weak annual plant which climbs by 
means of tendrils. 
