(Greek,desert and Citrus). Rutacex, tribe Citreae. Australian Desert Kumquat. Spiny shrub or small tree: leaves small, simple or emarginate, thick and leathery, alike on both sides; spines single, long, slender, axillary: flowers small, 4- (rarely 3- or 5-) merous, white, fragrant, borne singly, or 2 or 3 together in the axils of the leaves; stamens free, 4 times as numerous as the petals: fruits small, subglobose, oblate or pyriform, yellow, with a thin fleshy peel like that of a lime, 4- (rarely 3-5-) celled with 1 or 2 seeds in each cell; cells containing stalked subglobose pulp-vesicles filled with a pleasant acid juice. - Only 1 species of this subtropical Australian genus is known.

Glauca

Swingle (Triphasia glauca, Lindl. Atalantia glauca, Benth.). A shrub or small tree bearing edible fruits and occurring in Queensland and New S. Wales, Austral., in subtropical regions subject to severe cold and extreme drought. The leaves of this plant are small (1-1 1/2 X1/8-1/4 in.), emarginate, and show marked drought-resistant adaptations; both faces of the leaves show palisade cells, and stomates at the bottom of deep pits; the long and slender spines are borne singly in the axils of the leaves (see Fig. 1407): fruits subglobose, flattened or slightly pyriform (see Fig. 1408), usually 4-celled and containing globose stalked pulp-vesicles (see Fig. 1408); seeds small, with a longitudinally furrowed and rugose testa. Yearbook Dept. Agric, 1911, pl. 45, fig. 1. Jour. Agric. Research, U. S. Dept. Agric. vol. 2, pp. 85-100, figs. 1-7, pl. 8. - The fruits of this species are used by the settlers in Austral, for jam and pickles and ade is made from the juice. The Australian desert kumquat is the hardiest evergreen citrous fruit known besides being the only one showing pronounced drought-resistant adaptations; it bears in the wild state edible fruits with a pleasant acid juice and a mild-flavored peel.

These characteristics make this plant very promising for use in breeding new types of hardy drought-resistant citrous fruits It has been introduced into the U. S. by the Dept. of Agric, and is now growing in the greenhouse of the Dept. of Agric. and in the southern and western states. It can be grafted on the common citrous fruit trees, and can in turn be used as stocks for them Walter T. Swingle.

Spiny twig of young seedling of Ere mocitrus glauca. (X 1/3)

Fig. 1407. Spiny twig of young seedling of Ere-mocitrus glauca. (X 1/3)

Fruit of Eremo citrus glauca, entire and in cross section, showing stalked globose pulp vesicles and furrowed seeds. (Natural size)

Fig. 1408. Fruit of Eremo-citrus glauca, entire and in cross-section, showing stalked globose pulp-vesicles and furrowed seeds. (Natural size)