24 
KEY TO THE FAMILIES 
2. Corolla irregular. 
Stamens 10; corolla papillionaceous, that is pea-like; ovary 1-celled; style 
1, entire; leaves commonly compound. Leguminosae'; p. 95. 
Stamens less than 10. 
Corolla not 2-lipped. 
Sepals 2; petals 4, in dissimilar pairs; stamens 6. 
Fumariaceae; p. 38. 
Sepals 5, unequal; petals 3; stamens 8.Polygalaceae, p. 65. 
Corolla strongly 2-lipped or often only slightly irregular; sta¬ 
mens 4 or 2. 
Fruit a capsule; style 1 : stigma 2-lobed, rarely entire. 
Ovary and capsule 2-celled; green plants.... 
SCROPHULARIACEAE, p. 142. 
Ovary and capsule 1-celled; parasites... 
Orobanchaceae, p. 149. 
Fruit splitting into 4 nutlets; style 1. cleft at apex; stems square; 
herbage with the odor of mint. Labiatae, p. 135. 
B. Ovary inferior (adherent to the calyx). 
Stamens distinct, 4 or 5, rarely 2. 
Ovary 1-celled; flowers in involucrate heads or -short spikes; herbs... 
Dipsaceae, p. 153. 
Ovary more than 1-celled. 
Ovary 2-celled; flowers regular; herbs or shrubs. 
Rubiaceae, p. 150. 
Ovary 2 to 5-celled; flowers regular or irregular; erect or 
twining shrubs. Caprifoliaceae, p. 151. 
Stamens united into a tube around the style. 
Flowers not in heads. 
Stamens 3 ; leaves palmately lobed; tendril-bearing herbs. 
CUCURBITACEAE, p. 82. 
Stamens 5; leaves narrow; annuals. Lobeliaceae, p. 153. 
Flowers collected into a head and furnished with a calyx-like in¬ 
volucre, the whole resembling a single flower; stamens 5. 
Compositae, p. 154. 
Class II.—MONOCOTYLEDONS 
Parts of the flower usually in 3s; leaves parallel-veined (except Tril¬ 
lium) ; ours chiefly herbs, when perennial mostly with bulbs or rootstocks. 
A. Perianth none or calyx-like with scale-like divisions. 
Flowers not in the axils of dry chaffy bracts. 
Reed-like plants; inflorescence a dense cylindrical spike. 
Typiiaceae, p. 172. 
Trees; flowers on a spadix or fleshy spike. Palmaceae, p. 172. 
