364 PKACTICAL BOTANY 



Blueberries and huckleberries belong to two different genera 

 but resemble each other superficially. The former berry, borne 

 on bushes of several species, from six inches to ten feet in 

 height, is the more valuable, and is gathered over wide areas 

 of the northern United States and Canada. The " heaths," 

 or " blueberry barrens," on which the bushes grow in great 

 abundance, are often carefully reserved, to be picked for 

 the market. 



Ornamental shrubs of the Heath family are numerous and 

 highly prized. Best known among them are the rhododendrons 

 (Fig. 56) (including many species commonly called azaleas) 

 and the heathers. The so-called mountain laurel (Kalmia) is 

 somewhat cultivated, and is a characteristic feature of many 

 wooded hill and mountain sides in the northeastern states. 

 The "trailing arbutus" (EpigoBa), which is not, properly speak- 

 ing, an arbutus at all, is perhaps the favorite spring wild flower 

 of those regions where it occurs. The madrono (^Arbutus) of the 

 Pacific coast is one of the most beautiful trees of that region. 



334. Mint family (Labiate). This family comprises about 

 2600 species, mostly natives of warm or temperate regions. 

 The flowers are hypogynous ; stamens usually two or four ; 

 ovary f our-lobed, with a single style ; corolla bilaterally sym- 

 metrical. Most labiates are small shrubs or herbs, with square 

 stems and opposite leaves ; the whole plant is usually aromatic 

 and often glandular-hairy. 



For so large a family, the Labiatw ranks low in economic 

 importance. Many species, however, afford volatile oils, which 

 are of use in medicine, in cookery, or for perfumes. Some 

 beautiful garden plants belong to this family, one of the most 

 familiar being the scarlet salvia. 



335. The Nightshade family (Solanacea). This important 

 family numbers about 1300 species common in warm and 

 temperate regions. The flowers are hypogynous ; stamens five ; 

 ovary two-loculed, usually many-ovuled ; fruit a capsule (Fig. 

 300) or sometimes a berry. Most plants of the family are herbs, 

 but some shrubs and small trees occur, especially in the tropics. 



