How big is Rafflesia?

Rafflesia is a genus, or group of closely related species, of parasitic plants from the forests of Southeast Asia. The explorer shows its largest species, Rafflesia arnoldii, whose flower is about 1 meter (3.3 feet) across when fully open. As of 2026, the species has the largest known single flower of any plant.

Size

The size of a Rafflesia flower is its diameter, the width of the open flower across its red, petal-like lobes. Botanists give the flower of Rafflesia arnoldii as 1 meter in diameter. It grows in Indonesia, including on the island of Sumatra.

The genus has about 40 species, and the other species have smaller flowers. Rafflesia cantleyi of Peninsular Malaysia is 30–55 centimeters across on average. The smallest species described as of 2016, Rafflesia consueloae from Luzon in the Philippines, averages about 10 centimeters (4 inches).

The titan arum grows an enormous bloom. It is also called a corpse flower, the name Rafflesia carries as well. That bloom is a cluster of many small flowers, however, not a single flower, and the plant is not related to Rafflesia.

Size comparisons

About four basketballs lined up side by side would span a Rafflesia arnoldii flower.
The flower is about as wide as a dodo was tall, about 1 meter.
A 1-meter flower is a little more than half the height of a person 1.7 meters (5 feet 7 inches) tall.
A Rafflesia arnoldii flower is about 10 times as wide as the average flower of Rafflesia consueloae.

A plant that is almost all flower

Rafflesia arnoldii has no stem, no leaves and no true roots, and its flower is the only part that can be seen. The rest of the plant lives as thin threads inside tropical grapevines of the genus Tetrastigma, and it takes its water and food from the vine.

A bud breaks out through the vine's bark and grows slowly. In a study in Sumatra, buds took 339–497 days, about 11–16 months, to grow from a small bud to an open flower, and one opened when it was 22.4 centimeters (8.8 inches) across. The open flower lasted 5–7 days. The whole life cycle, from seed to flower, is estimated to take about three to five years.

Each flower is either male or female. Its smell of rotting meat attracts carrion flies, flies that seek out dead animals, and they pollinate the flower.

Rafflesia at risk

In 2023, researchers estimated that about 60 percent of Rafflesia species are at risk of extinction. Some of the forests they grow in are being cleared for farmland, and growing the plants away from the wild has proved difficult.

At the Bogor Botanical Garden in Indonesia, botanists began grafting infected vines onto the garden's own vines in 2004. The first bud appeared in 2010. Attempts to grow the plant from seed began in 2012, and in 2022 a Rafflesia arnoldii grown that way bloomed in the garden.