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.
A tree 6 to 12 meters in height, with a rounded or conical head, and a trunk upwards of 45 centimeters in diameter; bark smooth, grayish brown; young leaves and shoots sparsely pubescent, light green; leaves ovate, blunt, pointed or rounded, emarginate, smooth, dark, glossy green, leathery, margin crenate; petioles articulated, broadly winged; flowers produced singly or in cymose clusters of 2 to 20, sweet scented; calyx cupped, large; sepals 4 to 5, pointed; corolla white, 37 to 43 millimeters across; petals 4 to 5, slightly reflexed, fleshy, oblong; stamens 20 to 25; anthers large, abundantly supplied with pollen, proterandrous; pistil stout; stigma when ripe covered with a sticky, milky fluid; ovary 11 to 14 loculed; fruit large, oblate, globose or pyriform, light lemon or orange colored; flesh grayish or pink; juice sacs large, spindle shaped; flavor a mingling of acid, bitterness and sweetness or subacid; seeds large, light colored, wedge shaped or irregular, with prominent ridges surrounding broad, flat areas. Native to the Polynesian and Malayan Archipelagos.
The pomelo is the most widely distributed species in the genus, but here as in the orange the quality of practically all the fruit is wretchedly poor, dry and insipid with a very thick skin. With the exception of the panuban, described below, there are no variations worthy of notice in this genus.
Citrus decumana L. Pomelo, var. Panuban.
A spiny tree, 3 to 4 meters tall of robust growth; young growth pubescent; leaves 12 to 17 centimeters long, 4.7 to 8 centimeters wide, oblong ovate, crenate, coriaceous; base rounded; petiole 15 to 23 millimeters long, wing margins narrow, at most 18 millimeters broad, and cuneiform; flowers not seen; fruit 5.7 centimeters long, 7 centimeters in transverse diameter, oblate, with shallow apical cavity; surface smooth, lemon yellow; skin very thin; pulp contained in 11 to 12 locules, yellowish, fairly juicy, subacid, acidity and sweetness well blended, aromatic and well flavored; seeds large, polyembryonic.
The panuban is said to bloom about New Year and the fruit ripens in September to November; the trees are reported to be very prolific. The panuban has been reported only from Lias, Bontoc, where half a dozen trees are said to grow. Possibly the panuban may be an accidental hybrid between the pomelo and the orange or mandarin; if it is simply a mutation it is certainly one of the most striking in this species. However this may be, the pomelo character is strongly dominant in both the foliage and the fruit. Very well flavored, the fruit is too dry to be acceptable to a discriminating public, but it is not improbable that under cultivation the juiciness would increase. In such a case the panuban might become a fruit of commercial importance.