Gymnosperms

conifers

The most familiar gymnosperms are the ___________, the cone-bearing plants such as pines.

sporophylls

The ovules and seeds of gymnosperms (“naked seeds”) develop on the surfaces of specialized leaves called ________

ovaries

In contrast, ovules and seeds of angiosperms develop in enclosed chambers called ________.

Gymnosperms

_________ appears in the fossil record much earlier than angiosperms

Mesozoic era

The ________________ was the age of gymnosperms

progymnosperms

The gymnosperms probably descended from _________, a group of Devonian plants.

seeds

While the earliest progymnosperms lacked __________, by the end of the Devonian, some species had evolved them.

Adaptive radiation

__________ during the Carboniferous and early Permian produced the various phyla of gymnosperms.

ginko, cycads, gnetophytes, and conifers

The four phyla of extant gymnosperms are ______________________

Phylum Ginkgophyta

consists of only a single extant species, Ginkgo biloba.

Ginkgo biloba

This popular ornamental species has fanlike leaves that turn gold before they fall off in the autumn.

seed coats on female plants decay producing a repulsive odor to humans

Landscapers usually only plant male trees of gingko biloba, why is that?

Cycads

__________ (phylum Cycadophyta) superficially resemble palms.

Palms

_________ are actually flowering plants.

Circinate vernation

young leaves curved inward

dimorphic

Leaves usually __________ (two types of leaves in one plant)

prescence of permanent leaf scar

first Morphological Characteristics of Phylum Gnetophyta

Weltwitschia plants

from deserts in southwestern Africa, have straplike leaves.

Gnetum

species are tropical trees or vines

Ephedra

___________ (Mormon tea) is a shrub of the American deserts.

Morphological Characteristics of gymnosperms

• Prescence of permanent leaf scar

• Leaves usually dimorphic (two types of leaves in one plant)

• Foliage leaves

• Scale leaves

• Circinate vernation (young leaves curved inward)

Megasporangia

____________ are produced on megasporophylls

Microsporangia

______________ are produced on microsporophylls

Heterosporous

different types of spores that are different in structure, size and function

cones or strobili

Sporophylls aggregated to form

monosporangiage

Cones/strobili are ______ (having only one sporangium (or a single type of sporangium), a structure that produces spores)

ovule

Female cone, megasporophyll and ovule • Megasporangium aka the __________

short-lived

Male cone, microsporophylls and microspores. Males core are ______________; female cones live for many years

Cycas female cone

No definite female cone or strobilus in Cycad

Female strobilus

is an aggregation of spirally arranged megasporophylls

Megasporophylls

resemble foliage leaves

Megasporophylls

Similar to seed-bearing leaves

Cycas male cone

Male strobili (cone) are produced at the apex of the stem

gingko biloba

identify

Cycads

idenitfy

Weltwitschia

identify

Gnetum

identify

Ephedra

identify

circinate vernation

identify

dimorphic leaves

identify

female cone

identify

male cone

identify

cycas megasporophyll with ovules

identify

male cone

gingko biloba