Announcements Lab this week: Wear warm clothes for conifer walk Jim Brown Seminar Wed. 9 th UC Theatre
Coniferales (Conifers) 5 families worldwide, 3 in Montana Cupressaceae - Cypress Family Taxaceae - Yew Family Pinaceae - Pine Family
Conifers - Pinaceae (Pine Family) Pinus - PineLarix - Larch or TamarackTsuga - Hemlock Pseudotsuga - Douglas Fir Abies - Fir Picea - Spruce
Larix - Larch P. monticola Key features Deciduous needles in clusters Small cones w/ 3-parted bracts
P. albicaulis L. lyallii Subalpine Larch L. occidentalis Western Larch
Tsuga - Hemlock P. albicaulis T. heterophylla (coastal disjunct)
Pseudotsuga menziesii - Douglas-fir P. monticolaP. albicaulis
Abies - Fir P. monticolaP. albicaulis Key features Blunt evergreen needles Barrel-shaped cones held upright Cone scales dehisce (fall off)
A.lasiocarpa Subalpine Fir P. monticolaP. albicaulis A.grandis Grand Fir
Picea - Spruce P. monticolaP. albicaulis Key features Sharp needles Papery cones hang down twig w/ pegs scaley bark
P. monticolaP. albicaulis P. engelmannii Engelmann Spruce P. glauca White Spruce
Conifers - Pinaceae (Pine Family) Pinus - PineLarix - Larch or TamarackTsuga - Hemlock Pseudotsuga - Douglas Fir Abies - Fir Picea - Spruce
Cupressaceae - Cypress Family Key features Leaves usually scale-like (folded and flattened) Female cones small, either woody or “berry-like” Two genera in Montana Thuja (large trees) Juniperus (small trees or shrubs)
Thuja plicata - Western Red Cedar Coastal disjunct found on moister western slopes in Rockies Female cones
Juniperus - Juniper J. scopulorum Rocky Mtn. Juniper Dioecious shrubs/small trees Female cones berry-like J. communis Common Juniper low shrub w/needles worldwide distribution shrub/small tree scale leaves
Taxaceae - Yew Family Key features Dioecious shrubs/small trees Needles flattened; appear 2-ranked No cone - seed surrounded by a fleshy aril One genus/species in Montana (Taxus brevifolia)
Taxus brevifolia - Pacific Yew Coastal disjunct only in moist areas here (canyons etc.) Papery bark Arils (only on females)
Conifer Questions???? Cupressaceae - Cypress Family Taxaceae - Yew Family Pinaceae - Pine Family
Moving on to angiosperms: the vast majority of plants ConifersGingkosCycadsEphedra Seed plants Angiosperms 600 species 257,000 species ~135 mya
Plant life histories Different means to the same end: survival & reproduction
Lifespan and timing of reproduction Ideal plant strategy: 1)live forever 2)make lots of seeds every year Why not?
Lifespan and timing of reproduction Ideal plant strategy: 1)live forever 2)make lots of seeds every year Why not? Limited resources (light, nutrients, water etc.) tradeoff between survival/growth and reproduction (usually...)
Lifespan and timing of reproduction Life history strategies high adult mortality --> reproduce now! ex. weeds, vernal pool plants high seedling mortality --> just survive! ex. trees, grassland forbs
Lifespan and timing of reproduction: herbs (woody trees and shrubs are all perennial by definition) Annual 1st year: flowers, dies Biennial 1st year: makes rosette 2nd year: flowers, dies Perennial Lives for multiple years May or may not flower in any year Mimulus douglasiiOenothera biennisBalsamorhiza and Lupinus
Lifespan and timing of reproduction iteroparity - reproduce repeatedly semelparity- reproduce once, then die etc.
Lifespan and timing of reproduction Agave (Century Plant) extreme semelparity
Plants are sessile and modular vs.
Some consequences of being a plant can make own food (photosynthesis) can grow indefinitely & survive major damage BUT, can’t go look for a better place local competition for resources evolution of fungal/bacterial symbioses evolution of seed dispersal mechanisms can’t go look for mates evolution of pollination mechanisms
Competition for light affects plant growth form over evolutionary time over individual lifespans
terminal (apical) bud axillary bud node internode Angiosperm vegetative terminology leaf! stem
terminal (apical) bud axillary bud node internode Angiosperm vegetative terminology leaf! opposite leaves alternate stem or shoot whorled
Angiosperm vegetative terminology Basal leaves (at base of shoot) Cauline leaves (on shoot)
petiole Leaf parts blade stipule midvein margin pinnate palmate dichotomous parallel Leaf venation
stoma w/guard cells (regulates gas exchange) waxy cuticle (blocks water loss) Leaves need to uptake gas (CO 2 ) for photosynthesis, but also need to minimize loss of H 2 O through leaves mesophyll w/chloroplasts vein w/vascular tissue (water , sugar ) Plant water relations
Succulents (modified for water storage)
Artemisia tridentata (Asteraceae) Sagebrush foliage - Adaptation to dry/high sun conditions
Leaf forms simple unlobed simple lobed simple lobed (palmate) compound (palmate) compound (pinnate) compound (twice pinnate) entiredentate Leaf margins
How to figure out what is the leaf axillary bud is always at base of leaf (above the petiole)
Roots anchoring water and nutrient absorption water and carbohydrate storage TaprootFibrous roots Adventitious roots
Storage roots ?
Modified stems rhizome = horizontal, rootlike stem stem roots rhizome shoot buds tuber (extra-starchy rhizome)
Modified stems stolon = an aboveground horizontal stem with long internodes Saxifraga Fragaria plantlets
Saxifraga Fragaria
Saxifraga Fragaria Asexual or clonal reproduction Definition of “individual” depends on perspective genetic individual --> “genet” growth unit --> “ramet” Modularity => a continuum between growth and reproduction
Saxifraga Populus tremuloides (Aspen)