The Evolution of Seed Plants Feb. 18 and 23, 2011 life cycle of the pines origin of the seed Chapter 30

1)origin from ancestors similar to charophytes…

Abies amabilis - Oregon Pinus edulis - New Mexico

Pinus elliottii - Georgia coastPinus ponderosa - Colorado mts.

Pinus aristata - Colorado Sequoia sempervirens - Calif.

Figure 30.9 The life cycle of a pine (Layer 3)

POLLEN AND SEED CONES OF A PINE Seed cones pollen cones

Pollen Cones on a pine tree

Figure 30.10x1 Pine Sporangium with spores

Pine pollen in hand.

dispersed pollen Male gametophyte growing in nucellus early pollen

The target of the pollen is the ovule -- near the axis of the seed cone.

Integument Eggs Male gametophytes (Megasporangium)

Figure 30.10x3 Pine embryo

Figure 30.9 The life cycle of a pine (Layer 1) Integument

Figure 30.9 The life cycle of a pine (Layer 2) Integument

Figure 30.9 The life cycle of a pine (Layer 3) Integument

The Evolution of Seed Plants life cycle of the pines origin of the seed

COAL MEASURE SEQUENCE AT POINT ACONI, CAPE BRETON ISLAND. COAL SHALE (MUD STONE) with scattered leaf fossils SHALE with rootbearing Fossils in place

Seed fern fossils provide cluews to the origin of the seed.

Reconstruction of the seed fern Medullosa.

a coal swamp, dominated by spore-dispersed plants

Reconstructions of seed fern seeds

Origin of the Seed. I

Origin of the Seed. II