Flowering Plant Families, UH Botany

Magnoliidae: Laurales. The Lauraceae are nearly all woody trees and shrubs comprising 30 to 50 genera and about 2,000 species. An exception is the vining, leafless, parasitic genus Cassytha. The leaves are simple, without stipules, and usually alternate. The flowers are actinomorphic, usually bisexual, and possess a perianth of six, basally connate sepallike segments. The androecium most frequently comprises 4 whorls of 3 stamens each, although the inner whorls are often sterile. The filaments of the inner whorl usually have a pair of enlarged glandular appendages near the base. The anthers dehisce by means of commonly 4, upwardly opening flaps. The single simple pistil has a usually superior ovary with a single pendulous ovule in a solitary locule. The fruit is a berry or a drupe, often surrounded basally by the short, persistent perianth cup. Unlike other Magnoliidae, the endosperm is completely absorbed by the embryo in Lauraceae.

Cinnamomum burmannii, cinnamon, padang cassia. Note the 6 perianth segments, the large yellow glands on the inner filaments, and the pale yellow anther flaps on the outer stamens.

Cinnamomum zeylanicum, cinnamon. Note the persistent perianth cup at the base of the fruit.

Umbellularia californica, California bay leaf. Note 6 perianth segments, large yellow glands on inner filaments, and conspicuous flaps on anthers.

Persea americana, avocado. Note the trimerous nature of the flowers and the conspicuous glands on the staminal filaments.

Cassytha filiformis, kauna'oa pehu. This exceptional Hawaiian native member of the family is a stem parasite that survives by attaching itself to other plants. Notice the twine-like, orange stems and small round fruits. The stems are sometimes green, as seen in the lower photo. Although very small, the flowers are typical for the family, including the anthers that open by flaps. The anthers are greenish and the flaps are white in this flower.