The mandarin is the only species in the genus Citrus that has been at all systematically planted and cared for, even though this mostly consists in the planting the trees, now and then the clearing away of the weeds with cutlasses and the harvesting of the fruit. Nevertheless the quality of the fruit is uniform and very good. The mandarin district of the Philippines is confined to a small area principally around Santo Tomás and Tanauan, in the Province of Batangas, and, excepting imported fruit, all mandarins marketed in the Philippines are grown in the above-mentioned region. Scattered trees are found in most parts of the Archipelago. Aside from the tizon, which is described later, and which it is believed may be referred to this species, there are no well-defined varieties of the mandarin. Citrus nobilis var. papillaris Blanco. Tizon. (Plate II, b) A spreading, small tree, attaining a height of 6 meters or more, in habit similar to the pomelo; spines small, or wanting; leaves 10 to 14 centimeters long, 5 to 6 centimeters broad, ovate to elliptical oblong, crenate, dark-green and shining above, crinkly, base broadly acute, apex narrowly acute to almost acuminate and caudate; petioles 17 to 20 millimeters long with narrow wing margin; flowers not seen; fruit large from 6 to 10 centimeters in diameter, 170 to 580 grams in weight, somewhat compressed at basal half, usually ending in a more or less conspicuous nipple which, however, is sometimes wanting; apex flattened, or even depressed; surface smooth, pale greenish turning to orange yellow; skin medium thin; locules 10 to 11, separable from each other and the skin like the mandarin; pulp yellowish, subacid, very juicy, and of good flavor with marked "quinine" taste; juice cells large; seeds very few, rarely more than 7. The tizon is extremely rare and only a few trees are found in cultivation, confined to the citrus district of Batangas, Luzon. The trees are said to be quite prolific, and the fruit matures from September to December. This fruit, on account of its scarcity, is of no commercial importance. However, it would be an acceptable dessert or breakfast fruit, being a little more acid than the orange. It is said to be an introduction from Spain. The tizon is without doubt the C. papillaris described by Blanco in "Flora Filipinas." The tizon is believed to be a natural hybrid between the mandarin and the pomelo. It has inherited the loose-skinned character, large juice cells, and partial absence of spines, and leaf character of the first-named species to which it is (without the writer having had the opportunity to examine the flowers) unquestionably more closely related than to any other species in the genus. The tizon is represented in the citrus collection at the Lamao experiment station under Bureau of Agriculture No. 744 and 745. Citrus decumana L. Pomelo.