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Spinulum canadense — northern interrupted-clubmoss

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Facts

Northern interrupted-clubmoss in New England is confined to northern counties of Maine, New Hampshire and Vermont, usually on alpine plateaus and ridges, rarely at low elevations in Maine. Its stem features annual constrictions, hence 'interrupted' in the common name.

Habitat

Alpine or subalpine zones, cliffs, balds, or ledges, ridges or ledges

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Maine
  • New Hampshire
  • Vermont
Leaf shape
the vegetative leaves are short and scale-like
Spore leaf arrangement
the sporophylls are located on spore cones at the tips of the shoots or branches
Form of shoot
the plant has an upright stem, and the stem has simple branches
Horizontal stem
the horizontal stem is on the surface of the ground
Leaf differences
the vegetative leaves within a node are all similar in size and shape
Teeth on leaf edges
  • the edges of the vegetative leaves have no teeth
  • the edges of the vegetative leaves have tiny teeth
Spore leaf length
2.9–3.7 mm
Leaf outline
  • the vegetative leaves are widest above the base, then taper narrowly towards the tip (lanceolate)
  • the vegetative leaves are roughly triangular, widest at the base where the leaf joins the stem
  • the vegetative leaves are widest above the base, then broadly tapering towards the tip (ovate)
Show all characteristics

  • Clonal plantlets

    Gemma arrangement
    NA
    Gemma shape
    NA
    Gemma width
    0 mm

  • Leaves

    Leaf differences
    the vegetative leaves within a node are all similar in size and shape
    Leaf length
    3–5.9 mm
    Leaf orientation
    • the vegetative leaves are pressed against the stem
    • the vegetative leaves spread slightly away from the stem, at a steep angle
    Leaf outline
    • the vegetative leaves are widest above the base, then taper narrowly towards the tip (lanceolate)
    • the vegetative leaves are roughly triangular, widest at the base where the leaf joins the stem
    • the vegetative leaves are widest above the base, then broadly tapering towards the tip (ovate)
    Leaf ranks
    8 or 9
    Leaf shape
    the vegetative leaves are short and scale-like
    Pores on leaves
    there are pores on both sides of the vegetative leaves
    Spore leaf length
    2.9–3.7 mm
    Teeth on leaf edges
    • the edges of the vegetative leaves have no teeth
    • the edges of the vegetative leaves have tiny teeth

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Maine
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • cliffs, balds, or ledges
    • ridges or ledges

  • Spores or spore cones

    Cone base at stem
    the base of the spore-cone has a distinct stalk
    Cone stalk branching
    NA
    Cone thickness
    0 mm
    Cone width
    4.2–6 mm
    Length of cone
    8–21 mm
    Number of cones
    1–3
    Quillwort itssue covering spores
    NA
    Same or different spores
    there is only one type of spore present
    Spore girdle
    NA
    Spore leaf arrangement
    the sporophylls are located on spore cones at the tips of the shoots or branches
    Spore leaf lifespan
    the sporophylls wither and fall off at the end of the growing season
    Spore leaf orientation
    the sporophylls are pressed against the spore cone
    Spore leaf shape
    the spore-bearing leaves are small and scale-like
    Spore leaf teeth
    the edges of the spore-bearing leaves have tiny teeth
    Spore texture
    the spore surface has a net-like pattern on it (reticulate)
    Sterile tip of cone
    the spore cone does not have a slender, sterile tip (the whole cone produces spores)

  • Stem, shoot, branch

    Branch cross-section
    the outermost level of branches are round, elliptic or semicircular in cross-section
    Branch form
    the branches are similar in size to the main stem
    Constriction zones
    • there are constricted zones on the horizontal stem where the leaves are smaller smaller or closer together
    • there are constricted zones on the vertical stem where the leaves are smaller smaller or closer together
    Form of shoot
    the plant has an upright stem, and the stem has simple branches
    Horizontal stem
    the horizontal stem is on the surface of the ground
    Horizontal stem thickness
    1.2–2.3 mm
    Stem height
    70–270 mm

Wetland status

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

In New England

Distribution

Connecticut
absent
Maine
present
Massachusetts
absent
New Hampshire
present
Rhode Island
absent
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Vermont
extremely rare (S-rank: S1)

From Flora Novae Angliae dichotomous key

2.  Spinulum canadense (Ness.) A. Haines N

northern interrupted-clubmoss. Lycopodium annotinum L. var. montanum Tuckerman; 
 L. annotinum L. ssp. pungens Hultén; L. annotinum L. var. pungens La Pylaie ex Desv.; 
 L. canadense Ness.; L. dubium, auct. non Zoega (1772); L. pungens La Pylaie ex Iljin in
Komarov • ME, NH, VT; northern counties in New England. Northern and/or high-elevation areas, including open, alpine plateaus and ridges; rarely at low elevation (coniferous 
forests and bogs) in eastern and northern ME.

1×2. Spinulum annotinum × Spinulum canadense → This uncommon interrupted-clubmoss hybrid is located most frequently where the parent species are sympatric (e.g., on the higher mountains of ME and NH). It can be recognized by intermediate leaf length and dentition between the parental clones and shows 1–15 stomates per ½ adaxial surface on trophophylls from the middle of seasonal growth (compared with 25–53 per ½ adaxial surface in Spinulum canadense).

Native to North America?

Yes

Sometimes confused with

Diphasiastrum sitchense:
branches mostly 1.7-2.5 mm thick inclusive of the leaves, with pointed, but not bristle-tipped, leaves in 5 ranks (vs. S. canadense, with branches mostly 6-10 mm thick inclusive of the leaves, with bristle-tipped leaves in usually 4 ranks).
Spinulum annotinum:
leaves near the middle of seasonal growth 5.2-9.8 mm long and obscurely to evidently toothed, and spore cones mostly 17-43 mm tall (vs.S. canadense, with leaves near the middle of seasonal growth 3-5.9 mm long and obscurely toothed to entire, and spore cones mostly 8-17 mm tall).

Synonyms

  • Lycopodium annotinum L. ssp. pungensHultén
  • Lycopodium annotinum L. var. montanumTuckerman
  • Lycopodium annotinum L. var. pungensLa Pylaie ex Desv.
  • Lycopodium canadenseNess.
  • Lycopodium dubium, of authors not Zoega (1772)
  • Lycopodium pungensLa Pylaie ex Iljin in Komarov

Family

Lycopodiaceae

Genus

Spinulum