.ctia aver, N.th Austraila. CROUP OF COUTY-STEN TREES, THE STUDENT, AND INTELLECTUAL OBSERVER. JULY, 1868. THE GOUTY STEM TREE. (ADANSONIA GREGORII, MUELL.) BY JOHN R. JACKSON, A.L.S., Curator of the Museum, Royal Gardens, Kew. (With a Coloured Plate.) IN our last paper on the African species of Adansonia, we stated that the genus mustered only two species, one, as we there showed, a native of Africa, and the other a native of Australia, "A wide geographical difference in habit," our readers will no doubt say. It has been thought by some, that the two species might prove to be identical, and that the slight differences in their leaves, flowers, etc., might be the cause of accident, or some change in nature unknown to us, rather than a specific distinction; but in the general form of the Australian trees there is also some difference. It is known as well by distinct colonial names as by a distinct scientific one. Gouty Stem Tree, in allusion to its peculiar shape; or Cream of Tartar tree, or Sour Gourd, from the acid flavour of the pulp, are its colonial appellations. Cream of Tartar tree is derived from Krem tart boom, the name given by the Boers to the African tree. The Gouty Stem tree is known to botanists as Adansonia Gregorii, which name was given to it by Dr. Ferdinand Mueller, of Melbourne, in honour of Mr. A. C. Gregory, the commander of the expedition sent by the Royal Geographical Society to explore North-West Australia during the years 1855, 1856, and 1857. Adansonia Gregorii VOL. I.-NO. VI. Ꭰ Ꭰ is confined to this part of Australia, growing chiefly on the sandy plains and low stony ridges, and extending from the Glenelg River to the western shores of Arnheim's land. Though it is not found exclusively in the vicinity of the sea coast, it seldom occurs more than a hundred miles inland. Many of the explorers into the region of these trees have recorded their surprise and amazement upon first beholding them, yet comparatively little is generally known about them. Captain King, who surveyed the Australian coasts, says in his "Voyage on the Coasts of Australia," "Mr. Cunningham was fortunate in finding the fruit of a tree that was first seen by us at Cambridge Gulf, and had for some time puzzled us from its immense size and peculiar appearance. It proved to be a tree of the natural order Capparidaceæ, and was thought to be a Capparri. The gouty habit of the stem, which was soft and spongy, gave it an appearance of disease; but as all the specimens, from the youngest plant to the full-grown tree, possessed the same deformed character, it was evidently the peculiarity of its habit. The stem of the largest of these trees measured twenty-nine feet in girth, while its height did not exceed twenty-five feet.” If the trees seen by Captain King did not exceed twenty-nine feet in circumference, they were small in comparison with those seen by Gregory's expedition, as we shall presently see. It is not to be wondered that they should hastily have been conjectured to belong to the natural order Capparidaceæ, especially if the trees were leafless at the time, and the members of the expedition had no previous acquaintance with the African species; from the external appearance of the fruit alone one might readily believe it to be a Capparri, and Allan Cunningham first described it as Capparri gibbosa. The botanical differences between this tree and its African brother, as we have before hinted, are not very marked. The leaves in this, as in the African species, are digitate, the leaflets entire, acuminate, and when fully grown, from four to five inches long, very slightly pubescent above, and covered with white tomentum beneath. The petals of the flowers, like those of A.. digitata, are yellowish, or cream white, measuring quite four inches long. The calyx is oblong, entire in the bud, but splits into three or five lobes as the flower opens. The stamens are united into a column, but this column is not so long, neither are the filaments and anthers so densely crowded together in such a spherical mass as they are in the African species. The fruits in the Museum at Kew are not more than six inches long, and three or four inches wide; when ripe they assume a brownish yellow colour, and are covered with a soft pubescence, from the woody rind or shell a dark red gum exudes. From the foregoing description it will be seen that in the foliage and flowers of the two species there is a great similitude; the chief points of distinction seem to be that the leaflets are not so broad in the Australian tree as they are in the African; the calyx, also, is not so broad nor so regularly divided, the petals are narrower, and the filaments and anthers not so numerous or arranged together in such a globular tuft; it will also be observed that the fruits in the collection at Kew are smaller, though it is possible they may not be quite fully grown. The woodcut shows a leaf, an expanded flower, a flower-bud, and young fruit. Dr. Bennett, in his "Gatherings of a Naturalist in Australia," says: "Whether in the valleys, on the borders of rivers, or in the forests, the tree attracts the attention of the traveller by the extraordinary forms it assumes, so unlike in character to other trees constituting the sylvan scenery around, even amid the surprising variety seen in tropical forests. The trunks, resembling gigantic yams, are filled with abundance of mucilage, very similar to gum tragacanth, forming a reservoir of aliment calculated for the climate in which these trees grow. In the valley of St. Trinidad several of them were scattered about, and among them was one particularly |