CHAPTER XXVI 
PARASITES, ENSLAVED PLANTS, MESSMATES, 
CARNIVOROUS PLANTS 
404. Parasites. — A little was said in Chapter IV about 
parasitic plants, and the life history of one of them, the 
dodder, was briefly outlined ; another, the wheat rust, was 
discussed in Sects. 310-313. A parasitic plant is one 
which draws its supply of food partially or wholly from 
another living plant or animal known as the host. Some 
parasites are seed-plants, but a far greater number of 
species are spore-plants. 
405. Half-Parasitic Seed-Plants. — Half-parasites or par- 
tial parasites are those which take a portion of their food (or 
of raw materials to make food) from their host and manu- 
facture the rest for themselves. Usually they take mainly 
the newly absorbed soil-water from the host and do their 
own starch-making by combining the carbonic acid gas, 
which they absorb through their leaves, with the water 
stolen by the parasitic roots or haustoria imbedded in the 
wood of the host. Evidently the needed water may just 
as well be taken from the underground parts of the host 
as from the upper portions, and accordingly many half- 
parasites are parasitic on roots. This is the case with 
many of the beautiful false foxgloves (Gerardia), with the 
painted-cup (Castillea), and some species of bastard toad- 
flax (Comandra); see Flora. Usually these root-parasites 
are not recognized by non-botanical people as parasites at 
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