Coniferophyta, Gnetophyta Lab 13 Coniferophyta, Gnetophyta

Coniferophyta General features of the seed plants Common name: Conifers Synonyms: Pinophyta Sporophytes: Monoecious or dioecious; trees, shrubs Strobili: Simple or clustered pollen cone; compound seed cone with ovules on cone scales

Coniferophyta Undulipodia (“flagella”): None Representative genera: Abies, Cedrus, Juniperus, Metasequoia, Picea, Pinus, Podocarpus, Sequoia, Sequoiadendron, Taxodium Recognized by: Compound seed cones, needle or scale leaves

P Juniper branches Coniferophyta Top right: Juniperus mature foliage. Lower right: Juniperus juvenile foliage. Left: Mature and juvenile foliage on the same branch. Coniferophyta

D Pine branches Coniferophyta Note the curled bracts on the main stem, the fascicles in their axils, and the bracts forming a sheath around the base of each fascicle. Coniferophyta

D Podocarpus Note the broad leaves. Coniferophyta

D Microsporangiate strobili Left: Cluster of pollen cones on a pine tree. Right: preserved pollen cones. Coniferophyta

D Megasporangiate strobili Top: Bigcone spruce (Pseudotsuga macrocarpa). Bottom left: Coast redwood (Sequoia sempervirens). Bottom right: Bald-cypress (Taxodium distichum) Coniferophyta

A Pinus fertilization Coniferophyta Click on either photo to go to the Flash animation. Coniferophyta

A Pinus wood Coniferophyta Identify the pith, secondary xylem, growth rings, resin ducts, vascular cambium, cortex, and periderm. Coniferophyta

A Pinus leaf Coniferophyta Identify the epidermis, stomata, hypodermis, mesophyll, endodermis, transfusion tissue, xylem, and phloem. What are some xerophytic adaptations of pine needles? Coniferophyta

A Pinus pollen cone Coniferophyta Left: Stereoscope view of entire strobilus. Right: Close-up of microsporophylls with microsporangia. Coniferophyta

A Pinus pollen tubes Coniferophyta Note the sacci, pollen tube, generative nucleus, and tube nucleus. These are germinated in artificial culture, in a sugar solution with hormones. Coniferophyta

A Pinus young ovulate cone Left: Preserved pine seed cone, about the time that pollination takes place. Right: longitudinal section, showing cone scales and ovules. Coniferophyta

A Pinus young ovulate cone Left: Stereoscope view, showing entire strobilus. Right, top and bottom: an ovule showing the meiocyte and micropyle in the same section. Click on either one to go to the Flash animation. Coniferophyta

A Pinus mature embryo Coniferophyta Identify the female gametophyte, cotyledons, epicotyl, and hypocotyl. The radicle is shredded in each of these. Coniferophyta

P Pine seeds for dissection Coniferophyta

P Conifer seedlings from Lab 2 Distinguish the cotyledons from the first true leaves. Coniferophyta

Gnetophyta General features of the seed plants Common name: Gnetophytes Synonyms: None Sporophytes: Dioecious; shrubs, vines Strobili: Compound pollen cone; seed cone with 1-2 ovules

Gnetophyta Undulipodia (“flagella”): None Representative genera: Ephedra, Gnetum, Welwitschia Recognized by: Compound pollen cones, opposite leaves

D Ephedra Left: Ephedra growing in the Temblor Range of central California. Right: Ephedra in the San Bernardino Mountains. Gnetophyta

D Ephedra pollen cone Gnetophyta Note the bracts and microsporangia. This is a compound strobilus. Gnetophyta

D Ephedra pollen cone Gnetophyta Note the bracts and microsporangia. This is a compound strobilus. Gnetophyta

D Ephedra seed cone Gnetophyta Click on an image to see the Flash animation. Gnetophyta