balsam poplar

(Populus balsamifera)

               
Conservation Status

IUCN Red List

not yet assessed

 

No image available

NatureServe

N5 - Secure

SNR - Unranked

Minnesota

not listed

Wetland
Indicator
Status

Great Plains

FACW - Facultative wetland

Midwest

FACW - Facultative wetland

Northcentral & Northeast

FACW - Facultative wetland

Nativity

Native

Occurrence

Common

Habitat

Moist. Boreal forests, aspen parklands, lakeshores, riverbanks, swamp margins, marsh edges. Full or partial sun. Very shade intolerant.

Flowering

Early May to early June

     
Flower Color

Yellowish-green

     
Height

40 to 70

     

Identification

This is a medium-sized to large, fast-growing, short-lived, deciduous tree with a single trunk. It is often the largest tree in a stand of trees. In areas with periodic flooding a new root system is produced after a flood. Roots develop at the newly-submerged base of the trunk in the recently deposited soil. The result is a multilayered root system. On wet sites not prone to flooding the roots are shallow and wide spreading and the trees are prone to windthrow. The tree also produces root suckers and is sometimes colonial, especially in dryer areas. In Minnesota mature trees are usually 40 to 70 tall and 4 to 20 in diameter at breast height, though large individuals can reach over 80 in height and 24 in diameter.

Young trees have a clearly defined bole, with the trunk is distinct to near the top of the crown. The crown on young trees is cone-shaped. On older trees the the trunk divides at the top into two or more equally dominant, ascending, major branches. Other branches are relatively short and ascending. The crown on older trees is rounded.

The bark on young trees is somewhat smooth, greenish-brown to greenish-gray, and sometimes tinged with red. It has numerous raised, diamond-shaped, lighter colored bumps (lenticels). The lenticels eventually become vertical cracks. As it ages the bark becomes thick and darker gray or grayish-brown. On the lower trunk the vertical cracks develop onto deep, narrow, V-shaped furrows between flat-topped ridges.

First-year twigs greenish and hairy. Second-year twigs are reddish-brown, shiny, and hairless or hairy, with bright orange lenticels. Third-year twigs are moderately stout, grayish-brown, and round in cross section. A cut twig shows a solid, star-shaped core of spongy cells (pith) and has a bitter aspirin taste.

The bud at the end of the twig (terminal bud) is reddish-brown, hairless, egg-shaped, round in cross section, and to ¾ long. It is widest near the base and tapers to a sharp point at the tip. It is covered with 5 overlapping scales, is sealed with a red, sticky resin, and has a strong balsamic fragrance. Lateral buds are similar but narrower. They are appressed to the twig for most of their length but free at the tip. The first (lowest) scale is directly above the leaf scar. The leaf scars are nearly triangular and have 3 bundle scars. They are straight across at the top, not indented. There is no eyelash-like fringe of hairs where the bud meets the scar.

Two types of leaves are produced: early (preformed) leaves; and late (neoformed) leaves. Early leaves overwinter in the bud and are fully formed or almost fully formed before the buds burst in the spring. They are the first leaves to mature in the spring. Neoformed leaves are all of the subsequent leaves produced on long shoots. They are formed in the same season that they emerge.

All leaves are deciduous, alternate, and not lobed or divided (simple). They hang downward on yellowish, minutely hairy, flattened, to 2 long leaf stalks (petioles). The petioles are round in cross section but may have a shallow channel on the dorsal (upper) surface. There are usually 0 or 2, rarely up to 5, warty glands at the point where the leaf blade attaches to the petiole. The leaf blades are egg-shaped to narrowly egg-shaped, 2 to 3½ long and 1¼ to 2¼ wide. They are 1.2 to 2.3 times as long as wide. They taper to a point at the tip with straight sides along the tip. Sometimes the tip is slightly extended with concave sides along the very tip. They are rounded or slightly heart-shaped at the base. The upper surface is dark green, shiny, and hairless. The lower surface is pale green, covered with a whitish, waxy coating, and hairless. There are usually some reddish-orange (copper-colored) resin stains on the lower surface. The margins of early leaves appear almost untoothed or are shallowly toothed with usually 20 to 35 teeth per side. The teeth are rounded, forward pointing, and distinctly curved. The margins of late leaves are similar but with deeper teeth and usually 30 to 45 teeth per side. The leaves turn yellow In autumn.

Male and female flowers are borne on separate trees. They appear before the leaves in early May to early June. Both male and female flowers are borne in crowded, pendulous, short-stalked or almost stalkless clusters (catkins) of usually 50 to 70 flowers. The catkins emerge from lateral buds on 2nd year twigs. Male catkins are 1½ to 3½ long, stout, and densely flowered. Each male flower has 20 to 30 stamens with anthers that are bright red before shedding pollen. Female catkins are 2 to 6¼ long. The central axis (rachis) of the catkin is densely covered with short hairs. Female catkins elongate when fruiting, becoming 3½ to 6¾ long.

The fruit is an egg-shaped, ¼ to long, 2-valved capsule. Each capsule contains 30 to 44 seeds. The seeds are released in late May to June. They have cottony hairs attached and are dispersed by wind.

 
Similar
Species

Plains cottonwood (Populus deltoides ssp. molinifera) petioles are conspicuously flattened. The leaves are broadly triangular in shape and proportionately wider. They are no more than one third as long as wide. The base of the leaf blade is squared off. The leaf underside is not stained with copper-colored blotches. The buds are not aromatic. The rachis of the catkin is hairless.

Quaking aspen (Populus tremuloides) leaves are proportionately wider. The petioles are conspicuously flattened. Male flowers have 40 to 80 stamens. Female catkins are no more than 2 long.

 
Pests and Diseases

Pemphigus populicaulis (no common name) is an aphid that causes a gall at the junction of leaf blade and petiole. The opening in the gall is a slit running parallel to the direction of the petiole.


Distribution Distribution Map  

Sources: 2, 3, 4, 5, 7, 8, 28.


Record

Two trees share the title of Co-champion balsam poplar in Minnesota.

One is on private property in Brainerd, in Cass County. In 2015 it was measured at 88 tall and 130 in circumference (41 in diameter).

The other is on private property in Waskish, in Beltrami County. In 2015 it was measured at 80 tall and 121 in circumference (38½ in diameter).

 
Comments

The inner bark contains salacin, a precursor of aspirin.


Taxonomy

Family:

Salicaceae (willow)

 

Tribe:

Saliceae

 

Genus:

Populus (cottonwood)

 

Section:

Tacamahaca (balsam poplars)

 
Synonyms

Populus balsamifera ssp. balsamifera

Populus balsamifera var. candicans

Populus balsamifera var. fernaldiana

Populus balsamifera var. lanceolata

Populus balsamifera var. michauxii

Populus balsamifera var. subcordata

Populus candicans

Populus michauxii

Populus tacamahaca

Populus tacamahaca var. candicans

Populus tacamahaca var. lanceolata

Populus tacamahaca var. michauxii

 
Common
Names

balm of Gilead

balsam poplar

bamtree

eastern balsam poplar

hackmatack

Ontario balsam poplar

tacamahac poplar

tacamahaca


 

 

 

 

 

 

 

 

 

 

Glossary

Bundle scar

Tiny raised area within a leaf scar, formed from the broken end of a vascular bundle.

 

Catkin

A slim, cylindrical, drooping cluster of many flowers. The flowers have no petals and are either male or female but not both.

 

Lenticel

A corky, round or stripe-like, usually raised, pore-like opening in bark that allows for gas exchange.

 

Petiole

The stalk of a leaf blade or compound leaf that attaches the leaf blade to the stem.

 

Pith

The spongy cells in the center of the stem.

 

Rachis

The main axis of a compound leaf, appearing as an extension of the leaf stalk; the main axis of an inflorescence.

 

Simple leaf

A leaf that is not divided into leaflets, though it may be deeply lobed or cleft.

 

Sucker

A basal shoot rising from the roots or from a bud at the base of a shrub or tree.

       

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  Populus balsamifera
Blake C. Willson
 
  Populus balsamifera  
 
About

Balsam Poplar

 
     
  Populus balsamifera
Matt Lavin
 
  Populus balsamifera  
 
About

Native tree to 40 m tall, large numerous buds with sticky resin are the source of Balm of Gilead, leaf blades are lighter below than above and gradually taper to the terete petiole, common in the mountains along rivers, streams, among aspen groves, and in avalanche chutes and along roadsides. Populus balsamifera sometimes hybridizes with Populus angustifolia in Montana.

 
     

 

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  Balm Of Gilead Cottonwood Buds Habitat Wild Medicinals
MiWilderness
 
   
 
About

Uploaded on Feb 11, 2012

Balm of Gilead is a wild medicinal that is harvested from the buds of Cottonwood and Balsam poplar. Part one of this series shows the habitats where it is typically found.

Part two: http://youtu.be/KGEt0dzYT4w

Wild medicinals playlist: http://www.youtube.com/playlist?list=PL81021CE944A71DDF

 
     

 

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