Carnegiea gigantea

The Carnegiea gigantea is one of the defining plants of the Sonoran Desert. These plants are large, tree-like columnar cacti that develop branches (or arms) as they age, although some never grow arms.

Catesbaea spinosa

The tree about 4in thick and twelve or 14ft in height; the bark is smooth, of a greenish russet color, and the wood seemingly tough and hard. The leaves were like those of box, but smaller; they grow in clusters round the stalks, by intervals of an 1in space, more or less; from every cluster shoots forth two sharp pliant spines. The flowers are tubulous, of a yellow color about 6in long, hanging pendulous. They are monopetalous, being very small at the calix, and wide at the mouth, in form of a roman trumpet, except that their verge is divided into four deep segments, which are usually reflected back.

The fruit is of an oval form, and of the size of a pullet's egg; the flesh or pulp of it is like that of a ripe apple, covered with a smooth yellow skin. The middle of the fruit is hollow, containing many small triangular seeds. The fruit has an agreeable tartness and good flavour, and seems as if it was capable of being improved by cultivation, but is little known.

Ceiba boliviana

One of the more impressive trees, with large white flowers streaked with red, and a trunk armed with massive conical thorns.

Ceiba insignis, Chorisia insignis

The trunk becomes bottle shaped as it ages, and it is covered with stout spines, more decorative than really frightening. Can make a shade tree in warmer areas, or an interesting patio tree. Many bonsai them in large pots. In deep soil this can become a good shade tree, otherwise it is grown for its spectacular flowers and interesting shape. Pear shaped fruits containing a silky floss coming out of the seeds. Need a good drainage. Abundant water in the growing season can make a large tree quickly as they have been recorded to grow 5 meters (15 feet) a year in optimum conditions. Hardy to about 20 degrees F, although hardiness varies with individuals.

Ceiba pentandra

The ancient Maya of Central America believed that a great Ceiba tree stood at the center of the earth, connecting the terrestrial world to the spirit-world above. The long thick vines hanging down from its spreading limbs provided a connection to the heavens for the souls that ascended them. Even today, these grand trees are regularly spared when forests are cut it is a common event to see lone, isolated Ceiba trees proudly spreading their shady branches high above a pasture or agricultural field, a relict of the great forests that once were there. The giant limbs of the umbrella-shaped crown are laden with epiphytes (aerial plants) and provide a home for countless species of animals. Birds feed and nest in the tree's high perches, mammals use the enormous limbs as aerial highways, frogs raise their tadpoles in the tiny pools that collect in bromeliads, and insects reach the peak of their diversity in the canopy of giant trees like the Ceiba. Ceiba flowers open in the evening and are pollinated by pollen- and nectar-feeding bats. Their kapok-surrounded seeds are adapted for dispersal by wind.

Some varieties / cultivars have spiny trunks, others smooth.