Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Diphasiastrum digitatum — southern ground-cedar

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Southern ground-cedar is the most common ground-cedar in New England, and it is often used for decoration in wreaths. Another common name for this species is 'fan clubmoss,' which nicely describes the branches that are arranged in fan-like sprays.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, forests, meadows and fields

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • 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, with branches, those branches having further branches, and so on (tree-like)
Horizontal stem
the horizontal stem is on the surface of the ground
Leaf differences
the vegetative leaves within a node differ in size and shape
Teeth on leaf edges
the edges of the vegetative leaves have no teeth
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
Spore leaf length
1.7–2.6 mm
Leaf outline
  • the vegetative leaves are widest above the base, then taper narrowly towards the tip (lanceolate)
  • the vegetative leaves are long and very narrow (linear)
  • the vegetative leaves are roughly triangular, widest at the base where the leaf joins the stem
Show all characteristics

  • Clonal plantlets

    Gemma arrangement
    NA
    Gemma shape
    NA
    Gemma width
    0 mm

  • Leaves

    Leaf differences
    the vegetative leaves within a node differ in size and shape
    Leaf length
    0.3–5.5 mm
    Leaf orientation
    • the vegetative leaves are pressed against the stem
    • the vegetative leaves spread away from 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 long and very narrow (linear)
    • the vegetative leaves are roughly triangular, widest at the base where the leaf joins the stem
    Leaf ranks
    4
    Leaf shape
    the vegetative leaves are short and scale-like
    Pores on leaves
    there are pores, but only on the underside of the vegetative leaves
    Spore leaf length
    1.7–2.6 mm
    Teeth on leaf edges
    the edges of the vegetative leaves have no teeth

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of forests
    • forests
    • man-made or disturbed habitats
    • meadows or fields

  • Spores or spore cones

    Cone base at stem
    the base of the spore-cone has a distinct stalk
    Cone stalk branching
    the stalks bearing the spore cones are branched, with pairs of branches
    Cone thickness
    0.6–1 mm
    Cone width
    2–3 mm
    Length of cone
    14–40 mm
    Number of cones
    2–4
    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 are smooth, and without teeth
    Spore texture
    the spore surface has a net-like pattern on it (reticulate)
    Sterile tip of cone
    there is a slender sterile tip on the end of the spore cone

  • Stem, shoot, branch

    Branch cross-section
    the outermost level of branches are approximately rectangular in cross-section
    Branch form
    the branches are smaller than 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, with branches, those branches having further branches, and so on (tree-like)
    Horizontal stem
    the horizontal stem is on the surface of the ground
    Horizontal stem thickness
    1.3–2.7 mm
    Stem height
    150–500 mm

Wetland status

Not classified

In New England

Distribution

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

Conservation status

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

Maine
unranked (S-rank: SNR)
Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

2.  Diphasiastrum digitatum (Dill. ex A. Braun) Holub N

southern ground-cedar. Diphasium flabelliforme (Fern.) Rothm.; Lycopodium complanatum L. var. flabelliforme Fern.; L. digitatum Dill. ex A. Braun; L. flabelliforme (Fern.) Blanch. • CT, MA, ME, NH, RI, VT; throughout. Upland forests, borders, and fields.

1×2. Diphasiastrum complanatum × Diphasiastrum digitatum → Diphasiastrum ×‌verecundum A.V. Gilman is a rare ground-cedar hybrid 
of northern New England ( ME, NH, VT). The upright shoot branches are somewhat irregular (as in D. complanatum), but the stobilus stalk is stouter than in that species and often remains green after sporangium dehiscence. This hybrid may be more common than collections indicate, but the close similarity between its parents makes 
it difficult to detect.

2×4. Diphasiastrum digitatum × Diphasiastrum tristachyum → Diphasiastrum ×‌habereri (House) Holub is an infrequent ground-cedar hybrid known from MA, ME, NH, VT. It has winter bud constrictions on the lateral branches, similar to D. tristachyum, but is otherwise intermediate in branch width, relative size of trophophylls of the lower rank, and strobilus stalk branching.

Native to North America?

Yes

Sometimes confused with

Diphasiastrum tristachyum:
branches square in cross-section, as wide as 2 mm, with winter bud constrictions, and horizontal shoot buried deeper than 5 cm (vs. D. digitatum, with branches rectangular in cross-section, 2 mm wide or wider, usually without winter bud constrictions, and horizontal shoots at or near the surface).
Diphasiastrum complanatum:
lateral branches of upright shoots with winter bud constrictions and strobili mostly 10-25 mm tall, borne on very slender stalks that become stramineous prior to the release of the spores (vs. D. digitatum, with lateral branches of upright shoots lacking winter bud constrictions and strobili mostly 20-40 mm long, borne on relatively thicker stalks that remain green until after spore release).

Synonyms

  • Diphasium flabelliforme (Fern.) Rothm.
  • Lycopodium complanatum L. var. flabelliforme Fern.
  • Lycopodium digitatum Dill. ex A. Braun
  • Lycopodium flabelliforme (Fern.) Blanch.

Family

Lycopodiaceae

Genus

Diphasiastrum