SALTX WILLOW. 253 



tile oil, and as this is identical with that of gaultheria, their therapeutic 

 effects must necessarily be similar. 



ALNUS.— Alder. 



Alnus serrulata Aiton. — Black Alder, Tag Alder. 



Description. — Staminate flowers 3, rarely G, under each scale of the 

 catkin ; calyx 3- to 5-parted ; stamens as many as the lobes of the calyx, 

 with short filaments. Pistillate flowers 2 to 3 under each scale of the cat- 

 kin ; calyx of 4 small scales, adherent to the scales of the catkin. 



A slender shrub, 6 to 12 feet high. Leaves obovate, acute at the base, 

 rounded or blunt at the apex, sharply serrate, somewhat coriaceous, green 

 both sides, smooth or downy beneath. The flowers appear early in spring 

 before the expansion of the leaves, the staminate ones in long drooping 

 catkins, the pistillate, in short erect ones, which, in fruit, are ovate, and 

 persist for a long time upon the stem. 



Habitat. — Common in swamps and along the marshy borders of streams, 

 from Southern New England to Wisconsin and southward. 



Part Used. — The bark — not official. 



Constituents.— The only important constituent of alder bark thus far 

 discovered is tannin. 



Preparations. — Commonly used in decoction. 



Medical Properties and Uses. — Alder bark is alterative and astringent. 

 It is said to have been used in diarrhoea, and hematuria. In some sec- 

 tions of the country it is largely employed in domestic practice as a puri- 

 fier of the blood, both for the human subject and domestic animals. The 

 author has seen it employed many times in persons afflicted with succes- 

 sive crops of boils, with the happiest effect. Evidently such effects could 

 not have been produced by the tannin which it contains, hence there is 

 probably present some other principle of an active character which has not 

 as yet been isolated. 



Other species of alnus, both indigenous and exotic, possess similar 

 properties. 



SALICACE/E. 



Character of the Order. — Trees or shrubs with alternate simple, stipu- 

 late leaves. Flowers dioecious, in catkins, one under each bract, entirely 

 destitute of a floral envelope. Fruit a 1-celled, 2-valved, many-seeded pod, 

 the seeds provided with long silky down. 



A small order comprising two genera, namely, Salix and Populus. All 

 of them possess, to a greater or less extent, bitter tonic properties. 



SALIX.— Willow. 



Character of the Genus. — Scales of the catkin entire. Staminate flowers 

 of 2 to 10 distinct or united stamens, with 1 or 2 small glands. Pistillate 

 flowers with a small, flat gland at the base of the ovary. 



