Salix rotundifolia : Mountain Roundleaf Willow

Taxonomy

Scientific Name:

Kingdom: Plantae

Division:

Class: Dicoteldonae (two seed-leaves)

Family: Salicaceae (Willow Family)

Genera: Salix (Willows) (Classic Latin name for willow)

Species: rotundifolia (Round leaf)

Synonym(s): S.dodgeana, S.phlebophylla

English Name(s):

Mountain Roundleaf Willow, Round-leaved Willow

First Nation Names:



Description

Structure:

  • Dwarf shrub ours densely caespitose (densely tufted) and matforming.
  • Branches slender, largely under the surface of the ground, arising from a taprooted caudex (base).
  • Branches yellow-brown, glabrous (smooth).
  • Branchlets yellow-brown to reddish green, bearing 2-3 leaves.

Leaves:

  • Alternate.
  • Buds of all salix spp. (Willows) are covered by a single scale.
  • Leaves narrowly orbicular or elliptic in shape.
  • 4-6mm long by 1.7-3.6mm wide.
  • Margins entire (smooth) reddish, ciliate (marginal hairs) in some, revolute (rolled upward).
  • Upper surface of mature leaves glossy and glabrous (not hairy).
  • Leaves marcescent (withering) but not becoming skeletonized.
  • Petioles (stalks) short 0,8mm to 1.6mm long.

Reproductive Parts:

  • Flowers lacking a parianth(sepals + petals). Born in cylindrical catkins.
  • Plants dioecious (uni-sexual).
  • Catkins borne on branchlets with 2 leaves.
  • Pistillate (female) catkins often with only 2-4 flowers.
  • Bracts uniformly brown or bicolour, sparsely pubescent (hairy) with long trichomes (hairlike) appearing as cilia (margin hairs) around the margins.
  • Nectary reddish, equal or up to 3 times as long as stipe (stalk).

Seed:

  • Fruit a dehiscent (splitting open) capsule containing numerous small seeds.
  • Seed capsules (mature pistils) 4-7mm long, glossy nad reddish brown, glabrous (not hairy), or sparsely pubescent (hairy) at tip.

Not to Be Confused With:

  • Many of the erect shrub Salix (Willow) species can be hard to distinguish from each other. Useing the Keys and especially the Character Chart Key on the Salicaceae (Willow Family) Page should help.
  • Salix phlebophyla (Skeleton Willow) which can be distinguished by it less round leaves and haveing skeletonized marcescent (whithered) leaves.

Biology

Physiology:

  • Are insect pollenated. Both male and female flowers have nectaries to attract pollenating insects. Male pollen is also brightly coloured red or yellow to attract insects.
  • Several types of galls can be seen on willows. These are deformations of plant tissue caused by the physical actions or chemical secretions of insects.
  • Willow Roses are a type of gall that grows on some species of willow. It is caused by the larvae of Cecidomyia rosaria. The larvae through chemical secretions cause the leaves of the bud to grow in a rose petal like fashion.

Life Cycle:

Seasonal Cycle:

  • Catkins deciduous.
  • Leaves marcescent (withered) but not becomeing skeletonized.
  • Catkins appear with the leaves.

Ecology

Animal Uses:

  • In spring and early summer the catkins and young leaves are eagerly eaten by many mammals and birds.
  • Moose, caribou and deer all eat the twigs and young branches.
  • The twigs and bark are eaten by hares and lemmings.
  • Willow is an important food for bears and a secondary food for beavers.
  • Willow is an important food for many animals.
  • Winter buds are one of the principle winter foods of ptarmigan and grouse.

Habitat:

  • Moist turf in high alpine situations on calcareous plateaus and scree slopes.

Uses

Modern:

Industrial:

Medicinal:

    Food:

      Traditional Gwich'in:

      Folklore:

        Industrial:

          Medicinal:

            Food:

              Traditional Other:

              Folklore:

                Industrial:

                  Medicinal:

                    Food:

                      Images


                      Range Maps

                      World Range: Amphi-Berengian, Ours a cordilleran race; Disjunct from WY, MT, to YT, and AK.

                      Prov/State Abrev. List


                      In Yukon: In Richardson, Kluane, Ogilvie, and British Mountains.

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