DICOTYLEDONOUS PLANTS 133 



1. L. virginianum, L. WILD FLAX. Stem rather slender, erect 

 and cylindrical ; branches cylindrical. Leaves small, varying from 

 oblong to lanceolate or spatulate, the lower often opposite. Flowers 

 small, yellow. Capsules flattened at right angles to the pedicels. 

 Dry woods and pastures. 



2. L. usitatissimum, L. COMMON FLAX. Stem erect, with 

 corymbed branches at the top. Leaves narrowly lanceolate. Flowers 

 handsome, large, blue. Cultivated for the fiber. From Europe ; 

 introduced here to some extent. 



51. RUTACE-ffi. RUE FAMILY. 



Shrubs or trees. Leaves alternate, compound, without 

 stipules, marked with translucent dots. Flowers perfect or 

 variously imperfect. Sepals and petals 3-5 or none ; petals 

 hypogynous or perigynous when present. Stamens as many 

 or twice as many as the sepals, inserted on the glandular disk. 

 Pistils 2-5, often partially united. Fruit a capsule, a key- 

 fruit, or in the important genus Citrus (orange, lemon, lime, 

 etc., not here described) a leathery-skinned berry, the outer 

 part of the skin containing many spherical oil-cavities.* 



I. XANTHOXYLUM, L. 



Trees or shrubs ; bark, twigs, and petioles usually prickly ; 

 leaves odd-pinnate, marked with translucent dots. Flowers 

 in axillary or terminal cymes or umbels, monoecious or 

 dioecious. Sepals and petals 3-5 or none. Stamens 3-5, 

 hypogynous. Pistils 2-5, distinct. Carpels 2-valved, 1-2- 

 seeded. Seeds smooth and shining.* 



1. X. americanum, Mill. NORTHERN PRICKLY ASH, TOOTHACHE- 

 TREE. A prickly shrub, 8-12 ft. high, with aromatic bark. Leaves 

 pinnately compound; leaflets ovate-oblong. Flowers small and 

 greenish, in axillary umbels, appearing before the leaves. Petals 

 4-5. Pistils 3-5, the styles slender. Pods rather globose, somewhat 

 more than i in. in diameter, roughish, borne on a short stalk above 

 the receptacle, with a strong scent of lemon and tasting at first 

 aromatic, then burning. Rocky woods, ravines, and river banks. 



