gymnosperms

def keywords

evolved from ancient pteridophytes, seeds and woody stem, needle or scale like leaves, no fruit, no root hairs, vascular tissue less developed

how they became independent of water

one spore always stayed on the leaf-evolved into seed

the other spore carried away by the wind-evolved into pollen

the leaves producing htese two types evolved into flowers-reproduction became independent of water

pines

most abundant conifers, large forests northern hemisphere, cold and dry climates

pines unique features

flexible branches, evergreen, no root hairs, pine needles

flexible branches

snow slides off doesnt, break the branch

evergreens def

they constantly shed pine needles instead of at once

evergreen +s

able to utilize any little sunlight all year round, and right after snow melts, the shed pine needles break down slowly doe to high wax and resin content-acidic soil

evergreen why

very short period of optimal weather conditions— they cannot build a canopy and reproduce at the same time- only focus on reproduction during this time

no root hairs

less water-dependent on symbiotic fungi

relationship with symbiotic fungi

the fungi supplies mainly water to the tree, the tree supplies sugars to the fungi

pine needles

thick waxy layer deeply set stomata, needles can stand by themselves, in pairs or in clusters

resin

frost resistance, fill up wounds, protect against pests

cones

they are the flowers, there is no fruit, usually both cones can be found on each individual tree, no sepal or petals

male cones

produces pollens

female cones

produces the ovules-woth fertilization this becomes the seed

reproduction

wind pollinated

seed

a reproductive organ in resting state which contains the embryo the endosperm around it and the seed coat

resting state

when circumstances are optimal it will start to develop, until then the endosperm supplies the embryo with nutrients

importance

well adapted to harsh climates where no other plants this only food there, not cut down bc of agriculture bc hard to reach, they grow quickly, rots slowly