BotanyLab 11

Giant sequoiaSequoiadendron giganteum

Height: 250 ftDiameter: 27 ftAge: 3,200 yrs

Today's outline

- Quiz #5- Gymnosperms (four Phyla)

- Coniferophyta- Cycadophyta- Ginkgophyta- Gnetophyta

Gymnosperm Reproduction

- all seed plants are heterosporous! (we call the males microspores and the females megaspores)- produce naked seeds - gametophytes are nutritionally dependent on sporophytes- water not needed for fertilization

microspores

naked seeds

(megaspore mother cell)

(nucellus)

Coniferophyta-Most are monoecious (female and maleon same plant)

Pinus

Pine leaves (needles)

Eudicot leaf

Resin duct

fascicle

-needles are usually retained for 2-3 years

Cycadophyta

coralloid roots!

- tropical / subtropical- dioecious (female and male plant)- very abundant during Mesozoic era

Gingkophyta- only living member is Ginkgo biloba- dioecious and deciduous- commonly planted in cities- female plants do not produce cones

Ovules Pollen cones

Gnetophyta

Ephedra sp. Gnetum leyboldii

Welwitschia mirabilis

- Most are dioecious