Lagenaria Ser.
Lagenaria Ser., Mém. Soc. Phys. Genève 3: 26. 1825.
Type: Lagenaria vulgaris Ser.; replaced synonym: Cucurbita lagenaria L., Sp. Pl. 2: 1010. 1753; lectotype: Linn. 1151.1 (LINN), designated by C. Jeffrey in Milne-Redhead & Polhill (ed.), Fl. Trop. East Africa, Cucurbitaceae: 51. 1967; accepted name: Lagenaria siceraria (Molina) Standl.
Adenopus Benth. in Hook., Niger Fl.: 372. 1849.
Sphaerosicyos Hook. f., Gen. Pl. 1: 824. 1867 (nom. illeg.).

Annual or perennial, scandent climbers with herbaceous shoots and monoecious sex system. The leaves are simple, petiolate, with a pair of glands near the apex of the petioles. The leaf-blade is ovate-cordate or reniform in outline. The tendrils are bifid. The flowers are large, solitary, sweet-scented and opening in the evening or in the morning (Zimmermann 1922), pollinated by hawkmoths, moths (Noctuidae), butterflies, and honeybees (Morimoto et al. 2004). The receptacle-tube of male flowers is narrowly campanulate or funnel-shaped or cupular in female flowers with five sepals. The five petals are white, oblong-obovate, with retuse apex. The three stamens are inserted on the receptacle-tube in the center of the flower on free filaments. Two anthers are bithecous, one monothecous. The thecae are triplicate or much convoluted and contain tricolporate, perforate, medium-sized pollen (polar axis 60-77 µm, equatorial axis 60-81 µm, (Khunwasi 1998, Keraudren 1968)). The ovary is ovate or cylindrical with three placentae and numerous, horizontal ovules. The short style carries three bilobed stigmata. The fruit is fleshy, medium-sized to large, globose, bottle-shaped or ellipsoid, indehiscent, ripening green, often flecked with white, woody when mature. The numerous seeds are obovate, compressed, with distinct margin. The chromosome number is n = 11 in L. siceraria (Beevy & Kuriachan 1996, Keraudren 1968).

The six species grow along forest margins and on disturbed ground, usually near water in tropical Africa and Madagascar. Lagenaria siceraria is cultivated throughout the Tropics and Subtropics and in warm temperate regions. The species is of African origin and most likely reached the Americas floating across the Atlantic (Kistler et al. 2014).

The genus Lagenaria is sister to Peponium, from which it split about 12 million years ago (Schaefer et al. 2009), both in tribe Benincaseae (Schaefer & Renner 2011).

Literature

Beevy, S.S. and P. Kuriachan. 1996. Chromosome numbers of South Indian Cucurbitaceae and a note on the cytological evolution in the family. J. Cytol. Genet. 31: 65-71.

Keraudren, M. 1968. Recherches sur les cucurbitacées de Madagascar. Mém. Mus. Hist. Nat. B 16: 122-330.

Khunwasi, C. 1998. Palynology of the Cucurbitaceae. Doctoral Dissertation Naturwiss. Fak., University of Innsbruck.

Kistler. L., Montenegro, Á., Smith, B.D., Gifford, J.A., Green, R.E., Newsom, L.A., Shapiro, B. 2014. Transoceanic drift and the domestication of African bottle gourds in the Americas. Proc. Nat. Acad. Sci., USA 111: 2937–2941.

Morimoto, Y., Gikungu, M., Maundu, P. 2004. Pollinators of the bottle gourd (Lagenaria siceraria) observed in Kenya. Int. J. Trop. Insect. Science 24: 79-86.

Schaefer, H. and S.S. Renner. 2011. Phylogenetic relationships in the order Cucurbitales and a new classification of the gourd family (Cucurbitaceae). Taxon 60: 122-138.

Schaefer, H., Heibl, C., and S.S. Renner. 2009. Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events. Proceedings of the Royal Society B 276: 843-851.

Zimmermann, A. 1922. Die Cucurbitaceen. Beiträge zur Anatomie, Physiologie, Morphologie, Biologie, Pathologie und Systematik. Vols. 1 and 2. Jena: Fischer.