Conifers/Gymnosperms

New England Gymnosperms and Conifers

All conifers are gymnosperms, but not all gymnosperms are conifers.  Also, not all evergreens are conifers.  Rhododendrons and hollys are both evergreen, but bare flowers and so are angiosperms and not gymnosperms.

Gymnosperm Defined

Gymnosperms means naked seed, and refers to the fact that these plants do not have flowers so the pollen lands directly on the egg cells.  Not all gymnosperms are conifers.  Ginkos, for example, are a broadleaf gymnosperm (they don’t have needles).  The oldest gymnosperm fossils have been dated at 360 million years old.

Conifers Defined

Coniferous trees that bear cones are part of the gymnosperm group and most conifers have needles and are evergreen, however the bald cypressyew and tamarack are exceptions and lose their leaves in the fall.

Like all gymnosperms, they don’t produce flowers and have cones with naked seeds.  What this means is that during the time that pollen is released from the pollen cones, the female cones elongate slightly to expose the the ovules (egg cells).  Once fertilzed, scales grow over this area to protect the newly fertilized ovules so that seed development can begin.

Do evergreens ever lose their leaves?

It is a misconception that evergreens do not lose their leaves — think about a spruce-pine forest floor covered in needles.  Evergreens do lose their leaves (needles), but not all at once like deciduous trees do.

Conifers without woody cones

Some conifers don’t have woody cones. Yew have what looks like a berry, which is really a single seed surrounded by a fleshy layer derived from a single cone scale called an aril. These “berries”, though attractive in color, are poisonous.

Softwood vs Hardwood

In the lumber industry, conifers are also generally called softwoods, although there are some exceptions where a conifer may have harder wood than a broadleaf tree (douglass fir is harder than basswood.)

Gymnosperm Families

Pine Family (Pinaceae): Includes pines, spruce, firs, hemlocks

  1. Eastern White Pine Pinus strobus
  2. Red Spruce Picea rubra
  3. White Spruce Picea glauca
  4. Canada hemlock Tsuga canadensis
  5. Tamarack/ American Larch Larix larcina
  6. Balsam Fir Abies balsamea

Cedar or Cypress Family (Cupressaceae): includes cedars, cypress, junipers

  1. White Cedar Thuja occidentalis

Yew Family (Taxaceae)

  1. Canada Yew Taxus canadensis

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *


Biodiversity Exposed