Unformatted text preview: dormancy.
Acclimation: physiological changes that lead to
Many temperate species require cold period
before dormancy can break.
before Nastic Movements (p. 678; 639)
639 Rapid, reversable plant movements
Nyctinastic Movements up & down movements of leaves in
response to daily light/ dark cycles. Movement results from changes in size of parenchyma cells
in the pulvinus: (A joint-like thickening at a leaf/leaflet base).
Thigmonastic movements: Response to mechanical
stimulation. Sudden loss of turgor in cells of pulvinus. Result: leaves/ leaflets close rapidly Mimosa sp., Venus flytrap.
Neptunia: a native mimosa Open Closed Open Closed Heliotropism: Solar Tracking (p. 680)
Many species: Daily
movements orient leaves or
flowers parallel or perpendicular
to sun’s rays.
• Many legumes
• Arctic rose (video we'll see).
Movements involve pulvinus at
leaflet /leaf/ flower base.
leaflet Focus Plant 6: Thigmonastic Movements
Mimosa Sensitive Briars East Texas natives: Common along roadsides & in fields.
Bipinnate compound leaves.
Pink “powderpuff” inflorescences: stamens of individual flowers
collectively main showy feature.
Several similar species: M. strigillosa, M. Hystricina, M. Nutallii.
Touch triggers rapid closure of leaves.
Discourages browsing by deer, etc. Open Mimosa strigillosa Closed The End
The Mimosa Nutallii. Version 12.10...
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This document was uploaded on 03/28/2014 for the course BIO 131 at Stephen F Austin State University.
- Spring '14