26 CIRCULAR 143, U. S. DEPARTMENT OF AGRICULTURE 
This is an extremely variable species. Authors sometimes recognize three 
varieties, longipes, erpansus, and cadlopus. The variety longipes is distinguished 
by the extreme length of the stem, exzpansus by the breadth and expansion of 
its cap, and calopus, the most attractive variety, by the chestnut-colored stem. 
The plants are common and abundant, generally growing in large clusters united 
by the downy hairs of the base of the stems. They are to be found on rotten 
logs or old stumps of various kinds of trees from March to November. Both 
caps and stems of young plants are reported edible and as possessing a delicate 
flavor. 
LACTARIUS 
The distinguishing feature of the genus Lactarius is the presence 
of a white or colored milk, especially abundant in the gills. The 
entire plant is brittle and inclined to rigidity. The fleshy cap 1s 
more or less depressed and frequently marked with concentric zones. 
The gills are often somewhat decurrent, but in certain species are 
adnate or adnexed, unequal in length, and often forked. ‘The stem 
is stout, rigid, central, or slightly excentric. ; 
Species of this genus are generally terrestrial, often of very large 
size, and occur in considerable number in open woods or thickets. 
FIGURE 26.—Lactarius indigo. (Hdible) 
LACTARIUS DELICIOSUS. DELICIOUS LACTARIUS. (EDIBLE) 
In this species the cap is convex but depressed in the center when quite young, 
finally funnel shaped, smooth, slightly viscid, deep orange, yellowish or grayish 
orange, generally zoned, margin naked, at first involute, unfolding as the plant 
becomes infundibuliform ; the flesh is soft, pallid; the gills are crowded, narrow, 
often branched, yellowish orange; the stem is equal or attenuated at the base, 
stuffed, then hollow, of the same color as the cap except that it is paler and 
sometimes has dark spots. 
The cap is 2 to 5 inches broad; the stem is 1 to 2 inches long and 1 inch thick. 
This fungus is distinctive on account of its orange color and the concentric 
zones of light and dark orange on the cap and because of its saffron red or 
orange milk. A peculiarity of the plant is that it turns green upon bruising 
and in age changes from the original color to greenish. It is widely distributed 
and of common occurrence, appearing on the ground in woods, solitary or in 
patches, from June or July to October. 
This species has long been highly prized as an article of food and is thought 
to have been referred to by Pliny. A picture supposed to be this species has 
been found in a mural decoration in Pompeii. 
LACTARIUS INDIGO. INDIGO LACTARIUS. (EDIBLE) 
(Fig. 26) 
In this species the cap at first is umbilicate and the margin involute, later 
depressed or infundibuliform with margin elevated, indigo blue with a silvery 
gray luster, zonate, fading in age, becoming greenish and less distinctly zoned, 
