Flora of China 19: 19–20. 2011. 9. SIRAITIA Merrill, Pap. Michigan Acad. Sci. 19: 200. 1934. 罗汉果属 luo han guo shu Lu Anmin (路安民 Lu An-ming); Charles Jeffrey Neoluffa Chakravarty. Herbs, perennial, scandent, verrucose-glandular. Tuber spheroid, enlarged. Stems angular-sulcate. Leaf blade unlobed, margin sparsely dentate, abaxially pilose or densely tomentose. Tendrils spiralled above and below branch, 2-fid. Plants dioecious. Male flowers: inflorescence paniculate, bracteate; calyx segments 5, triangular, densely pubescent; corolla segments 5, lanceolate or obovate-lanceolate, base often with 5 scales; stamens 5, 4 connected in pairs, 1 free; anthers sigmoid. Female flowers solitary, paired, or 3 or 4 in raceme; staminodes 5, glanduliform; ovary ovoid; ovules numerous, horizontal; style stout, apex 3-lobed; stigma 2-lobed. Fruit subglobose or cylindric. Seeds subovoid or ovoid, winged, wing corky. 2n = 28. Four species: China, India (Sikkim), Indonesia, Malaysia, Thailand, Vietnam; three species (one endemic) in China. 1a. Male inflorescence cymose-paniculate, many flowered ............................................................................................ 1. S. sikkimensis 1b. Male inflorescence racemose or paniculate, 6–10-flowered. 2a. Seeds with 3-layered wing, wing marginally obtusely dentate; calyx segments 3–5 × 7–9 mm .......................... 3. S. siamensis 2b. Seeds with 2-layered wing, wing marginally only sparsely dentate; calyx segments 3–4 × 3–4 mm ............... 2. S. grosvenorii 1. Siraitia sikkimensis (Chakravarty) C. Jeffrey, Kew Bull. 36: 737. 1982. 锡金罗汉果 xi jin luo han guo Neoluffa sikkimensis Chakravarty, J. Bombay Nat. Hist. Soc. 50: 895. 1952. Stem angular, tomentose. Petiole 5–8 cm, tomentose; leaf blade cordate, 7–15 × 7–15 cm, abaxially tomentose, adaxially glabrous, margin entire, lowest lateral veins running parallel with margin of basal lobes. Male flowers yellow, 20–35 crowded on 8–14 cm axillary peduncle; rachis 3–5 cm; pedicels 1–2 cm; bracts leaflike, 7–15 mm; calyx tube campanulate, 10–15 mm in diam., tomentose; segments acute, 3–5 mm; corolla segments oblong-ovate, 8–10 × 3–4 mm, entire, ± constricted at apex, apex acute; stamens free, inserted at base of calyx tube, 1–2 mm; filaments 0.5–1 mm; anthers 1-celled, sinuate; con-nective broad, granular. Female flowers and fruit unknown. S Yunnan (Mengla) [India (Sikkim)]. 2. Siraitia grosvenorii (Swingle) C. Jeffrey ex A. M. Lu & Zhi Y. Zhang, Guihaia 4: 29. 1984. 罗汉果 luo han guo Momordica grosvenorii Swingle, J. Arnold Arbor. 22: 198. 1941; Thladiantha grosvenorii (Swingle) C. Jeffrey. Plant: all parts with yellow-brown pubescence and black glandular scales. Root enlarged, fusiform or subglobose. Stem and branches slightly robust. Petiole 3–10 cm; leaf blade ovate-cordate, 12–23 × 5–17 cm, membranous, apex acuminate or long acuminate; sinus semicircular or broadly ovate-cordate. Male flowers: inflorescence racemose, 6–10-flowered; pedun-cle 7–13 cm; pedicels slender, 5–15 mm; calyx tube broadly campanulate, 4–5 × ca. 8 mm, usually with 3 membranous scales; segments triangular, ca. 4.5 × 3 mm, 3-veined, apex long acuminate; corolla yellow; segments oblong, 10–15 × 7–8 mm, 5-veined, apex acute; filaments puberulent, ca. 4 mm; anthers ca. 3 mm. Female flowers solitary or 2–5 on 6–8 mm pedun-cle; calyx and corolla as in male flowers but slightly larger; staminodes 2–2.5 mm; ovary oblong, 10–12 × 5–6 mm, densely yellow-brown velvety, base obtuse-rounded; style ca. 2.5 mm; stigmas 3, enlarged, ca. 1.5 mm. Fruit globose or oblong, 6–11 × 4–8 cm, densely yellow-brown velvety and black glandular-scaly, ultimately glabrous. Seeds numerous, pale yellow, broadly ovate, compressed, 15–18 × 10–12 mm, base obtuse-rounded, with 2-layered wings, wings sinuate. Fl. May–Jul, fl. Jul–Sep. ● Forests on mountain slopes, riversides, thickets. Guangdong, Guangxi, Guizhou, S Hunan, Jiangxi. The fruit is used medicinally. 3. Siraitia siamensis (Craib) C. Jeffrey ex S. Q. Zhong & D. Fang, Guihaia 4: 23. 1984. 翅子罗汉果 chi zi luo han guo Thladiantha siamensis Craib, Bull. Misc. Inform. Kew 1914: 7. 1914; Momordica tonkinensis Gagnepain. Plants to 20 m; all parts densely yellow-brown pubescent and red (black when dry) glandular-scaly. Roots enlarged. Pe-tiole 3.5–10 cm; leaf blade ovate-cordate, 10–27 × 2–5.5 cm, membranous, palmately 5–7-veined. Male flowers: 5–15(to many) in a raceme or panicle; peduncle 2–12 cm; pedicels 15–30 mm; calyx tube broadly campanulate, 12–15 mm in diam.; segments ovate-triangular, 3–5 × 7–9 mm, 3-veined, apex ob-tuse; corolla pale yellow, 3.4–4 cm in diam.; segments ovate-oblong, 15–20 × 9–13 mm, margin with glandular hairs, base with 3 membranous scales, 5-veined, apex obtuse; filaments sparsely glandular hairy. Female flowers solitary or paired; calyx and corolla as in male flowers but smaller; staminodes (3–)5; corolla base with 3 scales; ovary ovoid, 12–15 × 9–10 mm, densely velvety and glandular-scaly, base obtuse-rounded, apex truncate; style 4–5 mm, glabrous, 3-lobed; stigma reni-form. Fruit subglobose, ca. 6 cm in diam., velvety at first, gla-brescent. Seeds numerous, pale brown, ovoid, 12–14 × 11–13 mm, ca. 4 mm thick, with 3-layered wings; wing corky, margin irregularly dentate, median 3–5 mm wide, lateral 1–2 mm wide. Fl. Apr–Jun, fr. Jul–Sep. Forests on mountain slopes; 300–700 m. W Guangxi, SE YunnanFlora of China 19: 19–20. 2011. [Indonesia, Malaysia, Thailand, N Vietnam]. The tuber is used medicinally.Flora of China 19: 19–20.