A thick, gray trunk gives rise to a broad, dense mat of branches, bearing leafy vegetation. The foliage glistens a shimmery green in sunlight because of its thick waxy leaves, a physical adaptation to the tree’s increased physical proximity to sunlight.
The trunk bulges slightly at mid-height because of stored water. This capacity to store water enables these trees to survive in an environment that cycles between rain and drought.
Bisav trees grow in sandy loam in temperate climates. They are highly adapted to intense sunlight, and periods of prolonged drought. Bisav trees live symbiotically with megaraffes and trunk horses, which are responsible for dispersing the tree’s pollen and seeds, respectively.
Bisav trees are autotrophs that combine carbon dioxide and nitrogen from the atmosphere and light from the Phygarian sun to generate tissues.
Bisav trees reproduce sexually. Each tree functions as either a male or a female, making flowers in late spring. The flowers are pollinated by the megaraffes whose long tongues retrieve pollen from the flowers of male trees and deposit it in the flowers of female trees. A pollinated flower produces a small fruit with a tough outer coat. Only trunk horses can digest this fruit, whose seeds usually survive the process to be dispersed to a new location when the megaraffe defecates. Seeds dropped in favorable locations will develop and grow to form a new tree.
The oldest organism in the Intergalactic Wildlife Sanctuary is a 329-year-old Bisav tree.