apetalous

In the polypetalous forms progression from hypogyny to epigyny is generally recognized, and where dorsiventrality with insect-pollination has been established, a dominant group has been developed as in the Leguminosae. The starting-point of the class, however, and the position within it of apetalous families with frequently unisexual flowers, have provoked much discussion.

Various - Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1

The forest trees on the ironstone ridges were stringy-bark, and on the grassy hills box, Moreton Bay ash, and a tree belonging to the natural order Leguminosae, with axillary racemes of white apetalous flowers, long, broad, flat, many-seeded legumes, large, bipinnate leaves, leaflets oval, one inch long, and having dark fissured bark; on the flat stiff soil grew ironbark, apple-tree, and another species of Angophora, with long lanceolate leaves, seed vessels as large as the egg of a common fowl and a smooth yellow bark.

John MacGillivray - Narrative of the Voyage of H.M.S. Rattlesnake, Commanded By the Late Captain Owen Stanley, R.N., F.R.S. Etc. During the Years 1846-1850. : Including Discoveries and Surveys in New Guinea, the Louisiade Archipelago, Etc. to Which Is Added the Account of Mr. E.B. Kennedy's Expedition for the Exploration of the Cape York Peninsula. By John Macgillivray, F.R.G.S. Naturalist to the Expedition. — Volume 2

Apetalous flowers may be considered as another form of monstrosity, and in Salpiglossis sinuata such a variety without a corolla made its appearance in the year 1892 in the nursery of Vilmorin. It appeared suddenly, yielded a good crop of seed and was constant from the outset, without any sign of vicinism or impurity.

Hugo de Vries - Species and Varieties, Their Origin by Mutation