184 SOME BRITISH PLANT GROUPS 
resemble the Bird’s-nest Orchis in sending up a stout 
leafless stem crowned with a spike of flowers. The 
different species display almost every colour except 
green, being red or brown or purple or yellow, and 
one blue. These plants live by attaching themselves 
to the roots of their host, and drawing in the nourish- 
ment they need for their own growth—robbery pure 
and simple. The seeds of the Broomrapes are very 
numerous and very light, and of singularly primitive 
structure. When they develop, they produce, not a 
young plant with root and stem, but a delicate spiral 
filament which grows down into the ground. Should 
this meet with a root of its host-plant, it adheres to it 
closely, and grows into a swollen knob at the point of 
attachment, which when mature sends up the flower- 
ing stem already described. Should a suitable root 
not be met with, the filament withers away and dies as 
soon as it has exhausted the small amount of reserve 
food stored in the seed. A parasite of a less sedentary 
habit, to be found in spring in our copses and hedge- 
rows, is the Toothwort (Lathrea Squamaria). This 
curious plant has underground creeping stems clothed 
with whitish, tooth-like, fleshy scales (curiously modi- 
fied leaves). In autumn and winter the stems lie 
dormant. In spring they send out delicate roots 
which attach themselves to the roots of trees of 
various kinds and suck nourishment from them, with 
the aid of which the plant sends up into the air fleshy 
cream-coloured stems bearing many drooping flowers 
of the same hue, the structure of which shows that the 
plant is closely allied to the Broomrapes. The Tooth- 
wort is a very harmless parasite, and the species of 
Broomrape also, though sometimes abundant on 
