What is Pimelea?

Pimelea, commonly called riceflower, is a genus of plant found in Australia and New Zealand. There are approximately 80 species in the genus, most of which are shrubs. Difficult to grow from seed, only a few species of this flowering plant are commonly cultivated. Though it poses no threat to humans, when the leaves are eaten by cattle, sheep and horses, they can cause gastro-intestinal problems and occasionally death.

A member of the Thymelaeaceae family, most Pimelea are flowering shrubs, though some species grow in the form of long-stemmed, woody vines. Thymelaeaceae are widespread throughout tropical and temperate climates, with the majority of species endemic to the Southern hemisphere. Most Pimelea species are native to Australia, New Zealand, and neighboring islands. These plants grow in a range of habitats, from the torpid jungles in the north of Australia, to the cool mountainous regions on the southern island of New Zealand. Each species is picky about where it grows, however, so most individual species have a narrower range of acceptable habitats.

While many species are difficult to grow, there are a few that are commonly used in landscaping. The plants produce small, inedible fruits that contain their seeds, but these seeds do not germinate easily. Plants are best cultivated through cuttings that can be planted in soil or grafted to hardy rootstalk.

Some of the more common varieties include Alpine Rice-Flower, or Pimelea alpina, and Yellow Rice-Flower, or Pimelea flava, which are both endemic to Southern Australia. Alpine Rice-Flower, as its name suggests, grows in cooler, alpine regions and displays clusters of five to 18 pink or white flowers at the ends of its branches. Remaining relatively small, Alpine Rice-Flower grows to heights of only about 1 foot (30 cm). Yellow Rice-Flower grows to 6.5 feet tall (about 2 m), and has similar clusters of yellow flowers at the ends of its long stalks.

Pimelea poses a problem for ranchers in Australia. In the early 1970’s, three species were officially recognized as the culprit in livestock deaths. Poisonings from consuming Pimelea cost millions each year in lost livestock and veterinary treatment. Though the plant has a strong odor and is not normally selected by livestock for food, it can be inadvertently eaten when mixed in with grasses. Symptoms of Pimelea poisoning manifest as gastro-intestinal problems and, in cattle, swelling under the jaw and on the chest. Livestock that eat this plant can also die suddenly due to heart failure.

Pimelea is a genus of plants within the Thymelaeaceae family, commonly known as rice flowers or banjine. These plants are native to Australia, New Zealand, and the Pacific Islands. They thrive in a variety of habitats, from coastal dunes to alpine heaths, showcasing their adaptability to different environmental conditions.

Cultivating Pimelea can be challenging due to their specific growing requirements and sensitivity to root disturbance. They prefer well-drained soils and a sunny position. Propagation is typically more successful through cuttings rather than seeds. Gardeners should handle these plants with care to avoid disrupting their delicate root systems.

Pimelea plants are recognized for their compact, bushy form and small, glossy leaves. They produce dense clusters of flowers that can range in color from white to pink or even red. The flowers are often spherical in shape, giving rise to their common name, rice flowers, due to their resemblance to grains of rice.

Yes, Pimelea plants are often used in ornamental horticulture for their attractive flowers and foliage. They are popular in native gardens and as cut flowers due to their long-lasting and visually appealing blooms. Additionally, some species have traditional medicinal uses among indigenous cultures.

Some species of Pimelea contain toxins that can be harmful to livestock, particularly Pimelea trichostachya, which causes a condition known as St. George disease in cattle. It's important for farmers to recognize and manage the presence of these plants in grazing areas to prevent poisoning.

Pimelea species play a role in their native ecosystems by providing habitat and food for various insects, including bees and butterflies, which are attracted to their flowers. By supporting these pollinators, Pimelea contributes to the overall biodiversity and health of the environments in which they grow.