HOW TO USE THE KEY xix 



"a. Petals separate" and "b. Petals united." The petals are found to be 

 separate, and the next choice is between the subdivisions "(1) Petals 1-3," 

 "(2) Petals 4," and "(3) Petals 5 or more." The plant in hand falls under 

 the first, where the decision rests between "(a) Petal 1," "(b) Petals 2" and 

 "(c) Petals 3." The latter is the proper number, and the next choice is 

 between "x. Sepals green, unlike the petals," and "y. Sepals and petals 

 more or less alike in color." Beneath the former are two possibilities, "(x) 

 Leaves grass-like; flower withering in a few hours," and "(v) Leaves not 

 grass-like; flower persistent." While the leaves are somewhat grass like, 

 the flower is persistent, and the choice must fall upon "(y)." Under the 

 latter, the decision lies between "m. Pistils 6-many, distinct; water-plants," 

 and "n. Pistil 1, compound, with 3 cells; land-plants." A cross-section of 

 the single pistil shows that it has 3 cells, and the plant is clearly a land-plant. 

 It is thus seen to belong to the Lily Family, Liliaceae, page 304. The next 

 step is to read the family description in order to see that the plant is 

 in essential agreement, and then it is traced through the key to genera in 

 the manner already indicated. The first choice lies between "1. Styles 

 distinct" and "2. Styles united." Under the latter, the choice is between 

 "a. Flowers axillary, solitary or 1-few in a cluster" and "b. Flowers term- 

 inal." The latter is true, and the next choice rests between "(1) Flowers 

 on a leafy stem." and "(2) Plants stemless." Under the former, the color of 

 the flower determines upon "(a) Flowers white or whitish to lilac" instead 

 of "(b) Flowers yellow to orange or purple." Under "(a)," the choice falls 

 upon "y" rather than "x," since the flowers are usually 1-2. The next 

 choice is between "(x) Flowers nodding; leaves ovate to lance-oblong" 

 and "(y) Flowers erect; leaves linear, grass-like." The latter is chosen, 

 and the final decision lies between "m. Flowers 1-3 in. wide; petals fringed 

 at base" and "n. Flowers 1-2 cm. wide; petals not fringed." The name of 

 the genus of the Mariposa Lily is thus found to be "Calochortus," and the 

 name of the species is found by turning to page 308. The plant should 

 first be compared with the description, after which the species is obtained 

 by deciding between "1" and "2". Since the gland is oblong and trans- 

 verse, and the anthers acute, the species concerned is "Calochortus Gun- 

 nisonii." 



