The sole included species is Idiospermum australiense − commonly known as idiotfruit, ribbonwood, or dinosaur tree − which is found only in two small areas of the tropical rainforests of northeastern Queensland, Australia.

It is a relic of the ancient forests of Gondwana, surviving in very localised refugia for 120 million years, and displaying features (of the flowers in particular) that are almost identical to fossil records from that time.

[5][6] It is a broadleaf evergreen tree growing to around 25 m (82 ft) tall,[7][8][9] with a maximum trunk diameter at breast height (DBH) of around 60 cm (24 in).

[7] All floral organs − bracts, tepals, stamens, staminodes and carpels − are spirally arranged and there is no clear distinction between sepals and petals.

[citation needed] Another unique feature of the ribbonwood is the fact that the fruit contain multiple cotyledons (embryonic leaves within the seed).

[5][7][15] His paper, titled Über primitive Ranales der australischen Flora, was published in the journal Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie, some ten years after he collected the specimens.

[11] Both areas are rainforested lowlands at the foot of high, rain-attracting mountains, with annual rainfalls of more than 3,000 mm (120 in), and alluvial soils.

Word of their discovery caught the attention of the German botanist Ludwig Diels, who ventured to the area in 1902 to collect specimens.

[7][15] By the time Diels published his paper (in which he noted that the species was rare and that he had the only known collections)[15] the lowland forests where he found it were being cleared for sugar cane farming, and were gone by the 1920s.

[14] In 1971 a grazier by the name of John Nicholas, who had a property in farmland in the Cow Bay area north of the Daintree River, discovered some of his cattle had died unexpectedly after suffering spasms.

[6][7] A government veterinarian, Doug Clague, examined the beasts and found large, unknown seeds in their stomachs, which appeared to have fallen from a particular tree on the property.

[6] Blake was eager to undertake a detailed study of the plant and visited the property himself a short time after, where he collected material from both the farm and from remnant forest along a nearby creek.

Upon closer inspection of the fruit and the flower specimens together, along with details of the size of the tree, it soon became apparent to Blake that this was not a species of Calycanthus, and he raised a new genus, Idiospermum, to accommodate it.