Fieldwork was carried out in October 2022 and using the standard herbarium technique described by (Djarwaningsih et al., 2002). The flowering and fruiting specimens were collected, examined, preserved, as well as deposited in Herbarium Bogoriense (BO). The morphological description of this species was determined based on the examination of the fresh plant, the voucher specimen, and the literature. To barcode this species, the internal transcribed spacer (ITS) region was used. Plant Genomic DNA Mini Kit from Geneaid was used to extract the DNA genome from silica gel dried leaves. A pair of ITS-5 (5’-GGA AGT AAA AGT CGT AAC AAG G-3’) as forward primer and ITS-4 (5’-TCC TCC GCT TAT TGA TAT GC-3’) as reverse primer was used for amplification of ITS regions according to White et al. (1990). Heat shock at 95 ºC for 3 minutes was used to start the PCR process and amplification was performed for 35 cycles in three steps. DNA was denatured at 95 ºC for 30 seconds and annealing was performed at 55 ºC for 30 seconds. Furthermore, DNA extension was conducted at 72 ºC for 90 seconds and the final extension occurred at 72 ºC for 5 minutes. Purification and Sanger sequencing were performed by a company, 1^stBase-Singapore, and sequences were deposited in GenBank.

Melothria pendula L. — Figure 1&Figure 2.

Melothria pendula L., Species Plantarum Ed. 1 (1753) 35; de Wilde & Duyfjes, Flora Malesiana I, 19 (2010) 107. — Type: Herb. LINN No. 51.1 (lecto LINN n.v., designated by Wunderlin (1978). — Melothria guadalupensis (Spreng.) Cogn. in A.L.P.P.de Candolle & A.C.P.de Candolle, Monogr. Phan. 3: 580 (1881). — Melothria fluminensis Gardner in London J. Bot. 1: 173 (1842). — Cucumis glaber Walter in Fl. Carol.: 240 (1788).

Description. Monoecious, perennial herb with fibrous roots and often a short woody taproot, trailing to procumbent, multi-stemmed at base, tendril on the upper side next to petiole, on fertile shoot next to pistillate flower and later staminate raceme in axil, unbranched, cylindrical, sparsely short-haired, aging glabrous. The stems are 5-ridged with rounded ridges, 2 mm in diameter but swollen at nodes, weak and flexible, striped, have internodes mostly 35-80 mm long, short-hairy aging glabrescent, and lack stipules absent. Furthermore, the leaves are alternate, entire, or with 3 or 5-shallowly lobed, petiolate has petiole 2-ridged with deep groove on upper side, a petiole shorter than blade, 1-1.7 cm long, striped light green, and dark green or reddish, often strongly bent at base and twisted, scabrous with short hairs, the hard hairs with persistent; blade suborbicular, ovate to broadly ovate in outline, 1.1-4.7 x 2.0-6.5 cm, cordate to deeply cordate at base, acuminate apex; margin remotely dentate or shallowly undulate. Male inflorescences have petiole pubescent, peduncle 1-1.5 cm, 7-8 dense flowers forming raceme, yellow color. Male flowers have pedicels 1-2.7 mm, perianth ca. 3 mm in diameter, receptacle tube ca. 1.5 × 1 mm, sparsely hairy on the outside, sepals ca. 0.3 mm long, petals glossy, yellow, diameter ca. 5 mm wide, lobes 1-1.3 × 2-2.8 mm, recurved at the tip, stamens 3, glandular filaments ca. 0.3 mm long, anthers ca. 0.8 mm long, and disk ca. 0.5 mm in diameter. Furthermore, female flowers are solitary, pedicel sparsely hairy, ca. 18 mm long, corolla ca. 6.5 mm in diameter, lobes ca. 2 × 3 mm, apex obtuse, shallowly recurved, ovary ca. 5 mm long, with ca. 1 mm neck, style ca. 1.2 mm long, stigmas about 1.2 mm long, with 3-lobes, and disk ca. 0.3 mm. Fruit berry, ellipsoid, ca. 1.5 × 1 cm, greenish when immature, purplish-black when ripe, sweet taste, while seeds are 15-24, obovate in shape, ca. 5 × 3 mm.

Distribution. Melothria pendula grows naturally in America, from Texas up to Argentina. This species has been introduced, grown wildly, and then naturalized in other regions, such as Asia and West Africa. The plants were previously recorded in Bali, Sulawesi, Sumatra (Indonesia), Peninsular Malaysia, Sabah (Malaysia), and the Philippines (Wilde WJJO & BEE, 2010); (Mustaqim & Putra, 2020). This study confirmed that the species was present in Halmahera, North Maluku Province as shown in Figure 2. Considering Melothria pendula was not yet used by the local people at the time, it was postulated that the creeping cucumber was naturally dispersed from Sulawesi to Maluku Islands through birds, animals, or ocean currents. The species is also found growing in Bogor Botanical Garden and in Cibinong Science Center Botanical Garden as well as in adjacent areas of Bogor Regency, West Java (Husaini et al., 2024).

Habitat and Phenology. Melothria pendula is typically found in disturbed areas, such as fields or roadsides as the native range. In Halmahera, this species grows on roadsides in open areas among shrubs, approximately 20 m above sea level (masl). Flowering and fruiting plants can be found at the same time (in October), throughout the year. In Cibinong, Bogor, the species grows well in open areas, but not in the shade.

Vernacular Name. Indonesia, Halmahera: timun tikus (mouse cucumber).

Uses. Melothria pendula is known to have medicinal properties, especially for diabetes. In Halmahera, this species is still being neglected.

Specimens Examined. Indonesia, Halmahera Island, North Maluku Province: East Halmahera Regency, Maba District, Geltoli Village, 0°55'36.7" N, 128°18'23.0" E, c. 20 m altitude, 19 X 2022, Arifiani et al. DA 2288; South Wasile District, Saramaake Village, 0°59'32.0" N, 127°57'19.5" E, c. 20 m altitude, 21 X 2022, Sulistyaningsih et al. LDS 631; Arifiani et al. DA 2319 (BO).

Notes. Melothria pendula, known to thrive in favorable growing conditions, has the potential to become an alien invasive species when the plants lack natural predators or competitors that would keep the population in check. In Indonesia, the name timun tikus or mouse cucumber is also applied to another species, namely Coccinia grandis (L.) Voight. The two species are similar in fruit shape, but differ in flower color and size, as well as the tips of the corolla lobes (yellow and small flowers with obtuse-shallow retuse corolla lobe tips in Melothria pendula vs. white and larger flowers with acute corolla lobe tips in C. grandis). In addition, the fruit of both species are ellipsoid and differ only on size, color (in mature), and surface pattern. Melothria pendula has a smaller fruit (0.8-1.5 × 1 cm), no longitudinal pattern, purple-black when ripe, while the fruit of C. grandis is more elongated 5-10 ×1.5-3.0 cm) with white longitudinal stripes and purple-red when ripe. The seed size is almost the same for both species, but differ in color. Melothria pendula is 5 × 3 mm in diameter, and a silvery color, while C. grandis 5-6 × 2-3 mm, creamy or light brown color.

The distribution of non-native alien species, Melothria pendula in Indonesia was recorded in Halmahera, North Maluku Province. This result broadened the distribution range from previous studies that have reported the occurrence of Melothria pendula in Sumatra, Sulawesi, Lesser Sunda Island, and Java. The study also improved the knowledge on geographic distribution of the genus, Melothria.