Diphasiastrum species

Ground Cedars

Ground Cedar, Photo © 1998 by Earl J.S. Rook
Ground Cedar
Photo © 1998 by Earl J.S. Rook

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Diphasiastrum, from the generic name Diphasium, and astrum, "inferiority or partial resemblance", hence, "false Diphasium"
  • Ground Cedar, from the resemblance of its scale-like leaves to those of the Cedars
  • Other common names include Ground Pine, Clubmoss


  • Kingdom Plantae, the Plants
    • Division Lycopodiophyta, the Clubmosses
      • Class Lycopodiopsida, the Clubmosses
        • Order Lycopodiales, the Clubmosses
          • Family Lycopodiaceae, the Clubmosses
            • Genus Diphasiastrum, the Ground Cedars
  • Also known as Lycopodium, Diphasium
  • North Country Species
  • Five species and six fertile hybrids occur in North America.


  • A creeping, evergreen, rhizomatous clubmoss, with occasional erect branches topped with slim cones.
  • Vertical stems multi-branched with scale-like leaves
  • Horizontal stems at or below surface of ground.
  • Cones cylindrical, ½"-2½", in upright candelabra-like clusters


  • Club Moss Identification for Amateurs

    1. Our North Country clubmosses are divided into four genera, based upon their leaves and cones.
      • Clubmosses with flat, scale-like leaves belong to this genus, Diphasiastrum, the so-called Ground Cedars, represented by three species in the North Country. All other clubmosses in our area have pointed leaves and a bristly appearance.
      • Clubmosses without cones belong to the genus Huperzia, represented by four species in the North Country, only two at all common.
      • A clubmoss with a cone which is merely a somewhat broader extension of the shoot belongs to the genus Lycopodiella, represented by a single species in the North Country.
      • Clubmosses with distinct cones and bristly leaves belong to the genus Lycopodium, the so-called Ground Pines, represented by six species in the North Country.
    2. If you have a Diphasiastrum, look closely at the ultimate branchlets. If they are cord-like, and nearly square in cross section, then you have Blue Ground Cedar (Diphasiastrum tristachyum). Confirm by:
      • bluish color (hence the common name)
      • leaves on the underside of the branchlet more or less the same size as those on the top and sides
    3. If the ultimate branchlets are narrowly blade-like and flat in cross section, usually green; underside leaves much smaller than lateral and upperside leaves, look at the overall pattern of the branchlets.
      • If the branchlets are irregular and almost shaggy in form, you have the common Ground Cedar (Diphasiastrum complanatum). Confirm by:
        • conspicuous annual bud constrictions
        • cone stalks, if present, regularly forked
        • cones mostly ½"-1", lacking sterile tips
      • If the branchlets are very regularly fan-shaped, you have Fan Clubmoss (Diphasiastrum digitatum). Confirm by:
        • absence of conspicuous annual bud constrictions
        • cone stalks mostly branching abruptly at base
        • cones mostly ¾"-1½", many with sterile tips


  • Circumboreal, mainly north temperate and subarctic.







  • Clonal, reproducing primarily by sprouting from rhizomes.


  • Very difficult.


  • Clubmosses can make attractive ground covers, but they do not transplant well.



Valley Internet Company
Return to Home Page
Send Feedback to Webmaster

Last Updated on 26 February, 2004