Dioscorea alata - Purple Yam

Purple Yam is a climber with variable tubers, usually spherical or conical (when cork brown or purplish black and transverse section purplish white), or oblate or cylindric, much branched (when cork brown or grayish yellow and transverse section white). Stem is twining to right, hairless, ridged, with 4 narrow, membranous wings, prickly at base. Bulblets are present, variable in shape. Leaves are simple; stalk green or purplish red, 4-15 cm; leaf blade green or purplish red, ovate, 6-15 x 4-13 cm, papery, hairless, base arrow shaped to deeply heart-shaped, tip shortly tapering or with a tail. Male spikes solitary or a few together, 1.5-4 cm, sometimes forming a panicle; axis obviously zigzagged. Male flowers have outer tepals 1.5-2 mm; stamens 6. Female spikes are solitary or 2 or 3 together. Purple Yam is found in Tropical Asia, including East Himalaya, at altitudes of 600-1200 m. Purple yams have edible tubers which have a mildly sweet, earthy and nutty taste, reminiscent of sweet potatoes or taro. Purple yam is most common in Philippine cuisine (where it is known as ube or ubi). It is often eaten boiled, baked, or as a sweetened dessert called ube halayá; the latter being a popular ingredient in the iced dessert called halo-halo. Flowering: November-January.