Populus balsamifera L. - syn.Populus tacamahacca Mill.; Populus candicans Aiton - Salicaceae
balsam poplar, hackmatack. tacamahac, Balm of Gilead, Balsampappel
Tree, up to 40m tall, native to North America; bark reddish gray, branchlets reddish brown, becoming grayish brown by third year; winter buds reddish, glabrous, resinous (resin red, abundant, very fragrant, balsamic); flowering buds clustered distally on branchlets; leaves petioled, blade usually narrowly ovate to ovate, rarely broadly ovate, abaxial surface often with reddish orange resin stains, glaucous, (veins prominent), adaxial dark green, glabrous; catkins moderately loosely (35-)50-70(-80)-flowered, flowers: discs shallowly cup-shaped, not obviously oblique, entire, 2-3(-4) mm diam.; stamens 20-30; capsules ovoid, (3-) 5-8 mm, glabrous, 2-valved. Seeds 15-22 per placenta.
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242430290
„The tree is known for its strong, sweet fragrance, which emanates from its sticky, resinous buds. The smell has been compared to that of the balsam fir tree.“
https://en.wikipedia.org/wiki/Populus_balsamifera
Major volatile components of balsam poplar winter-dormant buds are 1,8-cineole, (E)-nerolidol and (+)-α-bisabolol.
[Volatile constituents of balsam poplar: the phenol glycoside connection., Mattes, B.R., Clausen, T.P., Reichardt, P.B., Phytochemistry, 26(5), 1987, 1361-1366]
„Anyone that has ever walked into a poplar stand in the spring at bud break is impressed with the fragrance in the air. This fragrance comes from the volatile compounds in the buds and other parts of the tree… Various extracts from the winter buds of poplar were recognized by native peoples as having therapeutic value. For example, a salve or ointment (balm of Gilead) made by heating the winter buds in oil was used to relieve congestion.
[Zasada, J. C., & Phipps, H. M. (1990). Populus balsamifera L. Burns, RM et BH Honkala. Silvics of North America, 2, 518-529.] http://www.forestasyst.org/hardwoods/balsamifera.htm
Major components of the essential oil from the flower buds of balsam poplar are α-bisabolol (27.4%), δ-cadinene (6.9%), and (E)-nerolidol (5.8%), minor ones e.g. (E)-β-farnesene (1.9%), and 1,8-cineole (1.5%).
[Tisserand, Robert, and Rodney Young. Essential oil safety: a guide for health care professionals. Elsevier Health Sciences, 2013, 202]
Populus balsamifera L.: Trew, C.J., Ehret, G.D., Plantae selectae, vol.5 t.46 (1755)
http://plantgenera.org/species.php?id_species=1267654
Populus balsamifera, CC BY 2.0 Author: Matt Lavin, Montana, USA Wikimedia Commons