Specimen #7: Sweetshade or Native Frangipani Hymenosporum flavum
he native frangipani, or sweetshade tree (Hymenosporum flavum) arrived in the United States via Australia, a continent with many exotic botanic emigrés. In its native soil, it grows in rainforests and regions along the eastern coast. In this hemisphere, the sweetshade is popular in Southern California and San Francisco, where it provides a sensory accent to neighborhood streets.
Intensely perfumed and brightly colored, the tree’s blossoms attract a host of pollinators. Birds and honeybees are sweet on the tree by day, while moths flock to the pale-hued tubular flowers at night. The tree’s scent is stronger in the evening, an adaptation that magnifies its presence to pollinators that roam in the dark. As the tree matures, its cream-colored blossoms darken to a buttery gold. This color shift signifies that the sweetshade has begun to allocate resources towards its next product: the seed case.
Continuing the chroma progression, the pear-shaped cases are a light brown, and split open to reveal tight stacks of copper-colored winged seeds. The tree holds onto the woody capsules until the wind has peeled away each papery layer, and hundreds of seeds decorate sidewalks like a windfall of lucky pennies.
Beautiful and intricate, the seed cases are also the source of the tree’s name, Hymenosporum flavum: from the Greek words “hymen” (thin skin), “sporos” (seed). And the buttery blossoms are not forgotten — “flavus” is Latin for golden yellow.