Gymnosperm flashcards

Order: Cycadales

Characteristics:

  • Found in tropical and subtropical regions of the Southern Hemisphere

  • Insect-pollinated

  • Dioecious (separate male and female plants)

  • Brightly colored seeds

  • Pinnate leaves

Family: Cycadaceae

  • Genus: Cycas

    • Central thick mid-vein on leaf

    • Dioecious

Family: Zamiaceae

  • Genus: Zamia

    • Parallel vein growth

    • Dioecious

Order: Cupressales (formerly grouped under Coniferales)

Characteristics:

  • Leaves arranged in various planes (sometimes whorled), not in fascicles

  • Pollen cones located at the tips of branches, more common than seed cones

  • Scale-like leaves

  • Round pollen

  • Seeds with short lateral wings

  • Pine-like appearance

Family: Cupressaceae (Cypress Family)

Characteristics:

  • Scale-like leaves

  • Dioecious or monoecious species

  • Round pollen

  • 1-20 ovules per sporophyll

  • Seeds with short lateral wings

  • Shreddy bark

  • Genus: Juniperus (Junipers)

    • Dioecious

    • Can be tall trees or sprawling shrubs

    • Small overlapping scale-like leaves

  • Genus: Taxodium (Bald Cypress)

    • Deciduous conifer

    • Grows in swampy or wetland environments

  • Genus: Thuja

    • Soft, fan-like, dense foliage

    • Long ovoid/egg-shaped seed cones

  • Genus: Chamaecyparis (White Cedar)

    • Rougher texture than Juniperus

Order: Pinales

Characteristics:

  • Needle-like leaves, spirally arranged on stems

  • Monoecious

  • Woody cones

  • Saccate pollen (air sacs aid in wind dispersal)

  • Winged seeds

Family: Pinaceae (Pine Family)

Characteristics:

  • Needles attached to stems, leaving bumps when they fall off

  • Cones hang downward

  • Genus: Pinus (Pines)

    • Species: Pinus palustris (Longleaf Pine)

    • Species: Pinus taeda (Loblolly Pine)

      • 3-4 needles per fascicle (bundle)

      • Scaly bark

      • Large cones

  • Genus: Abies (Firs)

    • Cones grow upright

  • Genus: Picea (Spruce)

    • Stiff, sharp needles

  • Genus: Tsuga (Hemlocks)

    • Drooping branches with soft needles

Family: Taxaceae (Yew Family)

Characteristics:

  • Soft, linear, flat leaves

  • Dioecious

  • Round pollen

  • Single ovule per cone

  • Seeds covered with fleshy, flexible arils (red or yellow)

Order: Ginkgoales

Characteristics:

  • Fan-shaped leaves with dichotomous venation

  • Deciduous

  • Dioecious

  • Fleshy seeds with a strong odor (resembling vomit)

  • Family: Ginkgoaceae

    • Genus: Ginkgo

      • Species: Ginkgo biloba (The only extant species)

Order: Gnetales

Characteristics:

  • Dioecious

  • Unique, non-coniferous appearance

  • Advanced xylem tissue

  • Double fertilization (like angiosperms)

Family: Gnetaceae

  • Genus: Gnetum

    • Broad leaves, unlike typical gymnosperms

Family: Welwitschiaceae

  • Genus: Welwitschia

    • Distinctive two-leaf growth that continues throughout its lifespan

    • Found in the Namib Desert

Family: Ephedraceae

  • Genus: Ephedra

    • Shrubby, often found in dry regions

    • Source of ephedrine (used in medicine)