Here is an excerpt from Kings American Dispensatory along with photographs.  We have also included authors uses and experiences.  The language in text is from the previous century, so we have included a  vocabulary section.  (Note: we have found the use of a 1930-1940 medical dictionary to be very useful.)

Section 1: (Herbs associated with digestion)

ALNUS SERRULATA – TAG ALDER

Common Names:  Tag alder, Red alder, Black alder, Smooth alder, and Common alder.

Botanical Source and History                       (Photo below: Note saffron color of inner bark which stains brownish)

This shrub grows plentifully throughout the United States from southern New England to the western border of the Great Lakes and south ward.  It occurs as clumps or thickets, along the borders of streams, rivers, ponds, and in swamps, attaining a height from six to fifteen feet.  The stems are straight and the leaves smooth, somewhat coriaceous, obtuse, doubly serrate, round or blunt at the apex, and are accompanied by elliptical, obtuse stipules.  It’s flowers appear in March and April, before the leaves have expanded, and are of a reddish green color.  The pistillate flowers are born in an erect, and the staminate, in a drooping, catkin.  The fruit, which is ovate, often persists throughout the winter and gives rise to the name “Tag alder”.  The bark is brownish gray when fresh, and has an astringent, bitterish taste.

Chemical Composition

(Photo below: Tag alder in bloom)

The bark contains tannin, oils, and resin.  The first may be precipitated with gelatin.  A lesser quantity is found in the leaves.  Alnus is chemically antagonized by the mineral acids, alkalies, ferric salts, salts of lead and silver, and gelatin.

Authors Uses and Combinations

We have found Tag alder to be of particular benefit in digestive disorders.  It is one of the main ingredients in our digestive tonic.  It is combined in this formula with iris virginiana and wild cherry bark.  Each has its unique properties, but Tag alder is specifically used to increase waste and assimilation.  It is considered a good alterative and we use it in all skin diseases especially boils.  It truly is a very important native medicinal.

Action, Medical Uses, Dosage                                        (Photo below: This years cones)

To the taste Tag alder is bitter and astringent.  It powerfully increases retrograde metamorphosis and exerts a direct a tonic action upon mucous surfaces, aiding digesting and assimilation.  It is a true catalytic and a positive anti putrefactive agent.  Locally applied, the decoction stains the skin.  The drug stimulates the gastric mucous membrane and causes an increased flow of gastric juice.  Applied to the mammae, the leaves are said to decrease the lacteal secretion.  It is alterative, emetic, and astringent.

(Photo below: Last years cones)

This much neglected, but very important, remedy is a valuable agent scrofulosis, especially in those cases marked by glandular enlargements and suppuration.  Prof. Scudder speaks of it as one of the most valuable of our indigenous remedies, and points to its use in “superficial disease of the skin and mucous membranes, taking the form of eczema or pustular eruption.”  Administered internally and applied locally in these conditions, we may expect from alnus the best of results.  Impetigo, prurigo, herpes, and scorbutus, are diseases in which alnus will be of great utility.  In scurfy tetter of the scalp, in children, it is of much value.  The happiest results are obtained in its use in successive crops of boils.  It is a good agent in passive hemorrhages, particularly in hematuria, for which a decoction of the cones has also been used, and it is favorably mentioned for purpura hemorrhagica.  In marasmus of children, it is a much praised remedy.  Combined with rumex crispus, and used locally and internally, it is a good drug in nursing sore mouth ofmothers.  Alnus is an important drug in indigestion and dyspepsia, when resulting from deficient secretion of gastric juice and debility of the muscular coat of the stomach.  It may be associated with specific nux vomica.  In diarrhaea, caused by or attended with deficiency of the gastric secretion it serves an excellent purpose.   It has been used with good results as in an injection for leukorrhaea, and the leaves may scatter indurations of the mammary glands during the nursing period.  Dr. A.D.Ayer reports many cases of periodical hyper aesthetic rhinitis (hay fever) cured by alnus.  He recommends a distillate prepared after the manner of distillate of hamamelis.  The distillate is first used with an equal bulk of water and snuffed up the nostrils five or six times daily.  It may be increased to full strength in a day or two.  If desirous, it may be applied by atomization.  At night the nose is smeared with the distillate combined with petrolatum.  At the same time given internally: Rx distillate of alnus, gtt. 15 to 30 drops in a little water one hour before or after meals.  Dr. Ayer also recommends this preparation in the acute stage of gonorrhaea, and as an antidote to rhus poisoning.  The remedy is most effectual in an infusion (fresh alnus bark, 3j, aqua Oj); dose, a wine glass full.  Specific alnus, one to twenty drops.

Specific Indications and Uses

The specific use of this remedy is to improve nutrition and increase waste.  It is of particular value in scrofula, with feeble vitality, and chronic skin diseases exhibiting scaly or pustular eruptions.