A shrubby tree, 4.5 meters tall, with slender branches and small, weak spines; leaves 55 to 80 millimeters long, 20 to 25 millimeters broad, ovate to ovate-oblong or elliptical, crenulate, thin, of distinct fragrance, base rounded to broadly acute; apex obtuse, sometimes notched, petioles 20 to 30 millimeters long, broadly winged, about 14 millimeters wide, wing area somewhat less than one-half of the leaf blade; flowers in compact axillary or terminal cymes, 2 to 7, small, 5 to 9 millimeters in diameter, white, with trace of purple on the outside; calyx small, not cupped, petals 3 to 5; stamens 15 to 18, free, equal; ovary very small, globose to obovate; locules 7 to 9, style distinct; stigma small, knob like; fruit 15 to 20 millimeters in diameter, roundish in outline; base sometimes nippled; apex an irregular, wrinkly cavity; surface corrugate, greenish lemon yellow; oil cells usually sunken; skin very thin; pulp fairly juicy, acid, bitter with distinct aroma; juice cells very minute, blunt, containing a small, greenish nucleus; seeds small, flattened, sometimes beaked. The samuyao occurs sparingly in cultivation in Cebu and Bohol. Flowers were collected in May, partly grown fruits were also obtained, and ripe fruits have been collected in June, and from November to February, showing that the plant is more or less everbearing. The fruit is used by the Filipinos as a hair wash, and is of no economic importance. Throughout, the samuyao gives an impression of dwarfness, by its small size, weak spines, small, and thin leaves; the flowers are even smaller than in the biasong and the fruit is in all probability the smallest in the genus. In Bohol a somewhat more vigorous variety of samuyao was found which is named "samuyao-sa-amoo." The fruits of samuyao-sa-amoo are a little larger, and smoother, and longer than broad, otherwise similar to the samuyao. Samuyao, B. A. No. 2371, 2509 (Cebu), 2530, 4821 (Bohol); Samuyao-sa-amoo 2533, 4832 (Bohol). Citrus medica L. Citron.