modified plant parts storage stem (tuber): potato evidence: eyes are buds, chlorophyll floating leaves: Salvinia, Victoria prop roots: corn (from side of stem)

modified shoot onion fleshy leaf bases apical meristem at base

adaptive strategies parasites: plants that steal nutrients mistletoe takes water indian pipe takes food and water. epiphytes: plants sit on other plants evergreen: leaves survive dry season deciduous: leaves fall in dry season

fall leaf color chlorophyll degrades yellow/orange carotenoids visible red/purple anthocyanin is sunscreen

pigment locations anthocyanin: vacuole purple, red, blue 95% of cell volume (water soluable) chlorophyll (PS): chloroplasts green carotenoids: chromoplasts & chloroplasts yellow/orange/red other plastids store starch vacuole

adaptation to desert stems or leaves for water storage small SA/V: thick and fat green stems, spine leaves or branches stomata open at night convergent evolution

adaptation to low N habitat modified leaves for capturing animals plant, bacterial enzymes->N from victim 1) venus fly trap: hairs close cage 2) pitcher plant: slippery, hairs 3) sundew: sticky hairs

adaptations to temperate deciduous forest 1) spring ephemerals small, herbaceous (not woody) early start in forest bloom before shade 2) trees flower before leaves (redbud, maple) showy flowers after leaves (buckeye)

types of roots tap fibrous one main root, few side roots carrots, olive trees erosion on hillsides many roots hold soil grasses, incl. bamboo prevent erosion

adaptation to prairie deep roots (often fibrous) grasses w/rhizomes, basal meristems survive fire (req. to kill woody competitors)

adaptation to forest fire well formed trees little undergrowth no fire w/fire—> poorly formed trees much undergrowth

adaptation to forest fire little undergrowth quick fire trees survive— thick bark

symbioses with plant roots 1) N-fixing bacteria eg Rhizobium assoc. with legumes plant makes nodules bacterium gets sugar plant gets N crop rotations pesticides may interfere Mt. St. Helens recovery

symbioses with plant roots 2) mycorrhizae = “fungus roots” some roots modified, highly branched fungus gets sugar plant gets surface area, antibiotics >95% of vasc. plants agriculture, plant with fungal spores