612 FLOWERS OF GARDEN AND GREENHOUSE 
three, four, or five bulbs, according to the size of the variety potted. 
Their after-treatment should be the same as that recommended for 
Hyacinths in pots. 
Tulips are increased by means of seeds, and offsets from the old 
bulbs. These also should be treated as suggested for the propagation of 
the Hyacinth. Seedling Tulips do not begin to flower until their fourth 
or fifth year. 
Description of Plate 284. Tulipa gesneriana, the Garden Tulip. 
Plates 284 to 286. Several forms, to show variation in colour. Fig. 1 is a 
section of the flower. 
Plate 285. T. gesneriana, var. dracontia, the Parrot or Dragon 
Tulip. Fig. 1, flower after shedding the perianth. 
Plate 286. T. swaveolens, Van Thol’s, or the Sweet Tulip, in several 
colours, and showing the double form. Fig. 1 is the bulb, natural 
size. 
DOG’S-TOOTH VIOLETS 
Natural Order Lin1acex%. Genus Erythroniwm 
ERYTHRONIUM (Greek, erythros, red: the colour of flowers in original 
species). A genus of eight hardy bulbous perennials, of dwarf habit, 
with more or less oval, radical leaves, and solitary, nodding, rather large 
flowers, on a short scape. The perianth consists of six segments, which 
are either erect or turned back over the flower-stalk ; these segments 
are free to the base and equal in size, but the inner three are each 
provided with two blunt teeth near the base. There are six stamens, 
and the fruit is a three-celled capsule. One species—Z. dens-canis—is 
a native of Europe (whence it was introduced to England prior to 1596), 
and is found throughout Asia from Russia to Japan. The other species 
are all North American. ZH. americanum was introduced in 1665, and 
E. albidwm in 1824; the others are of recent introduction. 
ERYTHRONIUM AMERICANUM (American). Yellow 
Adder’s-tongue. Flower scape 3 to six inches high. 
Leaves elliptic, lance-shaped, marked with violet and white. Flowers 
bright yellow, 1 inch across, the segments blunt-tipped, turned back; 
March and April. 
E. DENS-CANIS (dog’s-tooth). Common Dog’s-tooth Violet. Flower 
scape 6 inches high. Leaves broad-oval, blotched with purple-brown 
and white. Flowers 2 inches across, purplish red, rosy, lilac, or nearly 
white; segments acute-tipped, turned back; March and April. 
Principal Species, 
