298 PLANT-LIFE 



world. There are instances in which it is lacking, 

 notably in some Palms and Conifers, but in relation to 

 the whole these exceptions are few. It is well known 

 that horticulturalists take the fullest advantage of the 

 capacity, for they regularly propagate plants by means 

 of slips, cuttings, runners, tubers, corms, bulbs, suckers, 

 buds, etc. The Begonia is frequently quoted as a 

 notable instance of reproductive possibilities. If a leaf 

 of this plant has slits made across its veins, and it be 

 pegged down to soil, buds will in due course appear, and 

 develop into ordinary plants. 



In the higher plants Vegetative reproduction occurs 

 in various modes. New individuals may arise from 

 rhizomes, or underground stems, as in the Iris, Coltsfoot, 

 Mint, Couch-Grass, and other plants. Such a plant as 

 the Coltsfoot is extremely difficult to eradicate from 

 ground it has determined to occupy. In winter its 

 underground stems are, of course, hidden from view, 

 and because of the decay of the foliage above ground 

 the existence of so great a subterranean potentiality is 

 not known. The gardener may dig up the stems, but 

 they readily break, and any portions with buds left in 

 the ground will give rise to new plants. Mint is equally 

 difficult to deal with, and as to Bishop- Weed (Mgo- 

 f odium Podagraria, Plate LIV.), an umbelliferous plant, 

 words fail to express the detestation in which the pesti- 

 lential weed is held by gardeners. Its underground 

 runners ramify in all directions, the strongest of them 

 penetrating to a depth at which they avoid the spade ; 

 a small piece of a runner left in the ground may produce 

 a big colony. Dog's-Mercury (Mercurialis ferennis) and 

 the Stinging-Nettle (Urtica dioica) owe the greater part 



