Reabsorbtion. Occuring more commonly within the nephron system than filtration, this is a form of active transport which takes the the useful substances for the body from the tubules and places them back into the blood filled capillaries.
Oleanders are shrubs, but they are _big_ shrubs. Most of the varieties in cultivation top out at 8 to 12 feet tall and about the same width. The wild form, and some of the older cultivars used for windbreaks top out at 20 x 20 feet.
Oleander grows best in humidity, and by pruning, watering the soil and keeping oleanders in the sun, they can grow quite big. Learn some dangers of growing oleander, such as a new disease that's threatening the plant's survival, in this free video on gardening from the owner of a landscaping company.