(botany) A tree that bears wild apples.

Ceiba pentandra, a tree of the tropical Americas and west-central Africa, with white flowers, cultivated in south-east Asia for its seed fibre.

Melia azedarach, a deciduous or semi-evergreen tree with poisonous fruit, native to India, Southeast Asia, and northern Australia.

(graph theory) A tree structure which includes all vertices of a graph.

(mathematics, set theory) A tree (T, <) of height ω₁, each of whose levels is at most countable, and has at least ℵ₂ branches.

A hierarchy or tree of people (employees, students etc.) in which each person forwards a message to the next person down the line. The tree is arranged so that a single person can easily forward messages to all people.

Polyscias kikuyuensis, a plant in the Araliaceae family, endemic to Kenya. / Firmiana simplex, a plant in the Malvaceae family, native to Asia.

Any of several West Indian trees with more or less leathery foliage, but otherwise dissimilar, such as Pisonia subcordata, Cordia alba, and Cupania glabra.

The giant sequoia or wellingtonia, Sequoiadendron giganteum

(Eastern Weald) A tree with edible fruit, Sorbus torminalis, native to central and southern Europe and neighboring parts of Asia and Africa.