中文名（Chinese Name）：量天尺
学名（Scientific Name）：Hylocereus undatus (Haw.) Britton & Rose
英文名（English Common Name）：nightblooming cactus
别名（Chinese Common Name）：火龙果
异名（Synonym）：Cereus tricostatus Rol.-Goss.；Cereus trigonus var. guatemalensis Eichler；Hylocereus guatemalensis (Eichlam) Britton & Rose；Hylocereus tricostatus (Gosselin) Britton & Rose
科属（Family & Genus）：仙人掌科（Cactaceae）量天尺属
形态特征（Description）：攀援肉质灌木，长3-15米，具气根。分枝多数，延伸，具3角或棱，长0.2-0.5米，宽3-8（-12)厘米，棱常翅状，边缘波状或圆齿状，深绿色至淡蓝绿色，无毛，老枝边缘常胼胀状，淡褐色，骨质；小窠沿棱排列，相距3-5厘米，直径约2毫米；每小窠具1-3根开展的硬刺；刺锥形，长2-5 (-10)毫米，灰褐色至黑色。花漏斗状，长25-30厘米，直径15-25厘米，于夜间开放；花托及花托筒密被淡绿色或黄绿色鳞片，鳞片卵状披针形至披针形，长2-5厘米，宽0.7-1厘米；萼状花被片黄绿色，线形至线状披针形，长10-15厘米，宽0.3-0.7厘米，先端渐尖，有短尖头，边缘全缘，通常反曲；瓣状花被片白色，长圆状倒披针形，长12-15厘米，宽4-5.5厘米，先端急尖，具1芒尖，边缘全缘或啮蚀状，开展；花丝黄白色，长5-7.5厘米；花药长4.5-5毫米，淡黄色；花柱黄白色，长17.5-20厘米，直径6-7.5毫米；柱头20-24，线形，长3-3.3毫米，先端长渐尖，开展，黄白色。浆果红色，长球形，长7-12厘米，直径5-10厘米，果脐小，果肉白色。种子倒卵形，长2毫米，宽1毫米，厚0.8毫米，黑色，种脐小。花期7-12月。
分布（Distribution）：产中美洲，我国南方广泛栽培。
用途（Use）：FOC Vol. 13 Page 211
Hylocereus undatus (Haworth) Britton & Rose, Fl. Bermuda. 256. 1918.
量天尺 liang tian chi| Cactaceae  | Hylocereus
Cereus undatus Haworth, Philos. Mag. Ann. Chem. 7: 110. 1830.
Plants clambering or sprawling. Stems deep green, 3-15 m. Joints 20-50 × 3-8(-12) cm, winged or angled, margins of wings or angles coarsely crenate, horny. Areoles 3-6 cm apart, 2-5 mm in diam. Spines 1-3(-6) per areole, spreading in various directions, gray-brown, conic to subulate, 2-5(-10) mm. Flowers 25-30 × 15-34 cm. Receptacle tube funnelform. Sepaloids with greenish midrib and mostly white margin, lanceolate-linear to linear, 10-15 × 1-1.5 cm, margin entire, apex acuminate, reflexed. Petaloids erect to spreading, white, narrowly oblanceolate, margin entire or erose. Filaments cream, 5-7.5 cm; anthers linear, ca. 4.5 mm. Style cream, 14-20 cm, stout; stigmas 20-24, exserted, 2-2.3 mm, slender. Fruit red, globose to ellipsoid, 7-12.5 × 6-12 cm, with numerous triangular scales, umbilicus small; pulp white. Seeds obovate, ca. 2 × 1 mm. Fl. July-Dec.
Trees, rocks, maritime scrub; sea level to 300 m. S Fujian, S Guangdong, SW Guangxi, Hainan, Taiwan [perhaps native to Mexico and Central America; widely introduced and escaped in tropical Asia, E Australia, and South America].
This species was first introduced to China in 1645. It is usually cultivated as a hedge, or for its edible fruit. The flower is often eaten in a vegetable soup in S Guangdong.
（责任编辑：徐晔春）