New Medicinal Plant Variety of Trichosanthes tricuspidata Lour . ( Cucurbitaceae ) from Northeastern Thailand

Objectives: This research was carried out for describing, illustrating and treating a new medicinal plant variety in the genus Trichosanthes. Methods: This research was carried out by collecting plant specimens in the Northeastern Thailand. Morphological characters were studied and compared with the closely related taxon and taxonomic literatures. Results: T. tricuspidata subsp. rotundata var. longirachis, was found. This plant is described and illustrated here and treated as a new variety. It differs from the other of T. tricuspidata subsp. rotundata by having the following combination characters: Comparatively stout herbaceous climber up to 20 m long, tendril 3–5-brached, probract obovate with obvious glands, mature blade unlobed or 3-shallowly lobed with 1-2 short angles, blade not deeply lobed (unlobed blade found in juvenile plants), blade size 5-11 cm diameter and raceme rachis length 10–130 cm. Its fruits and seeds were used as medicinal parts. Conclusion: Totally, three subspecies and four variety of T. tricuspidata in Thailand have been recorded so far. Important comparative morphological characters with some closely related variety are discussed. The local people used it as medicinal plant.


INTRODUCTION
Trichosanthes was first treated by Linnaeus 1 in the family Cucurbitaceae with approximately 100 species distributed from South and East Asia to tropical Australia and the eastern Pacific. 2,3Trichosanthes species are easily to recognized by the following characters: mostly climber habit, dioecious plant, mostly branched tendrils, receptacle tube elongate, apex of petiole without glands, distinctly fimbriate petals, and often brightly colored fruits. 4mong Trichosanthes species found in Thailand, T. tricuspidata Lour.subsp.rotundata W.J.de Wilde and Duyfjes was first treated by de Wilde and Duyfjes. 5o far, three subspecies (i.e.T. tricuspidata Lour.subsp.javanica Duyfjes and Pruesapan, subsp.rotundata W.J.de Wilde and Duyfjes and subsp.tricuspidata) and two varieties (i.e.T. tricuspidata Lour.subsp.javanica Duyfjes and Pruesapan var.javanica and var.flavofila W.J.de Wilde and Duyfjes) have been reported. 6,7After examination of plant specimens collected from Khon Kean and Maha Sarakham provinces, Thailand, and careful comparison with known taxa, this plant is distinct from other closely similar plants and is treated here as a new variety.trict, Mahasarakham province during field trips in the Northeastern Thailand between the years 2010-2015.All specimens were pressed and dried before their morphological characters were studied in laboratory.In addition, careful studies and comparisons with both living and herbarium specimen (including the type specimen) in main herbaria in Thailand (BK and BKF) and Europe were performed.Taxonomic literatures [2][3][4][5][6][7][8][9][10]12 were used in this study.

RESULTS
The Cucurbit plant field trips for this research were done in the Northeastern Thailand and many plant specimens were collected to study their morphology.After the plant materials were careful examination, there were T. tricuspidata subsp.rotundata specimens that their morphology differs from this subspecies.The new plants are recognized here as a new variety of this subspecies, namely T. tricuspidata Lour.subsp.rotundata W.J.de Wilde and Duyfjes var.longirachis Chatan and W. Prom prom.The characteristics of this plant is a comparatively stout herbaceous climber up to 20 m long, tendril 3-5-brached, probract obovate with obvious glands, mature blade unlobed or having 3-shallowly lobed with 1-2 short angles, blade not deeply lobed (unlobed blade found in juvenile plants), blade size 5-11 cm diameter and numerous cystoliths; blade simple, orbicular in outline, 5-11 × 5-9 cm; margin of mature blade unlobed or 3-shallowly lobed with 1-2 angles (not deeply lobed) and with fine remote denticulate (un-lobed blade found in juvenile plants); if lobes present, lobe apex acute or acuminate or obtuse; blade texture membranaceous to subchartaceous ; upper side green when fresh and brown when dry, under side pale green when fresh and pale brown when dry; upper side covered by numerous cystoliths and underside glabrous except for numerous cystoliths on vein; veins 5, slightly straight; gland on blade absent.Male inflorescences raceme; peduncle 5-10 cm long, rachis obviously zigzag, 10-130 cm long, covered by numerous short min hairs and some cystoliths.Buds clavate.Bracts ovate or orbicular, concavo-convex, persistent, 22-25 × 20-25 mm; fresh specimens whitish green with green veins and the bract color is slightly darker near its apex, dry specimens brown; green glands on both surfaces when fresh, glands on adaxial side raised, the glands brown when dry; margin slightly triangular lobed or incised at upper part and entire at lower part; lobes apex acute or obtuse; base rounded or truncate; both surfaces covered by min hairs.Pedicels 3-4 mm long, green, caducous.Receptacles tube 25-35 mm long; ca.10-13 mm diam.at throat and ca.

Description
Large perennial herbaceous climber, comparatively stout, up to 20 m long, climbing on small to tall shrubs or trees.Old stem thick, 20-30 mm diameter, pale brown.Young leafy stems 2.5-3 mm diameter, surfaces glabrescent, striate and covered by cystoliths, green when fresh and brownish when dry; dioecious.Probract obovate, ca.6 × 4 mm, surface with obvious glands, pale green when fresh and brown when dry. Tendrils 3-5-branched.The 5-branced tendrils usually found in large leafy branches.Leaves alternate; petiole (1-) 2.5-4.6 cm long, covered by T. tricuspidata subsp.rotundata var.longirachis collected from Kantharawichai district, Mahasarakham province is described and recognized as a new variety, so until now two varieties of this subspecies are recognized.Totally, three subspecies and four variety of T. tricuspidata in Thailand have been recorded so far.This plant variety was used as the medicinal plant by local people.Its fruits and seeds were used as purgative, and seeds were used as laxative.

DISCUSSION
Trichosanthes consists of ca. 100 species in the world and 17 species in Thailand.A slightly complete revision for the Thai taxa begin in 2004. 11owever, a more recently revision of this genus for Flora of Thailand was published by de Wilde and Duyfjes. 4 After examination of Trichosanthes specimens collected from the Northeastern Thailand and comparison with known taxa, there were T. tricuspidata subsp.rotundata specimens that differ from the other specimens.Therefore, T. tricuspidata subsp.rotundata var.longirachis was described as a new variety.It is characterized by the combination characters as follows: Comparatively stout climber up to 15 m long, tendril 3-5-brached, probract obovate with obvious glands, mature blade unlobed or having 3-shallowly lobed with 1-2 short angles (unlobed blade in juvenile plants), blade size 5-11 cm diameter, raceme rachis length 10-130 cm.

CONCLUSION
After examinations of plants collected from the Northeastern Thailand, both dried and living specimens, herbarium specimens in the main herbaria in Thailand (BK and BKF) and Europe and careful study of literatures, 2.5 mm diam.at base; expanded portion covered by dense hairs inner side; narrow portion glabrous near base and covered by glandular hairs near expanded portion.Sepals ovate-triangular, 10-12 mm long and 4-8 mm wide at base; margin serrulate at lower part; surface with green glands when fresh and brown when dry. Petals obovate, 13-15 × 8-14 mm, threads 12-15 mm long, white with pale green veins.Stamens 3, pale brown, filaments 2-4 mm long, synandrium 10-13 mm long.Pistillode linear, 4.5-11 × 1-1.5 mm.Female inflorescences and florets not seen.Fruits globose.raceme rachis length 10-130 cm.The taxonomic treatment is shown below.