Lagenaria siceraria var. hispida (calabash, "Yugao")

Japanese name: ユウガオ （夕顔）
Scientific name: Lagenaria siceraria var. hispida

[Overview]
A vining annual.
The stems creep along the ground and grow long, sometimes exceeding 20 m.
The leaves are simple and alternate, heart-shaped, with margins shallowly lobed in a palmate pattern.
There are male and female flowers, both white, with the corolla tip 5-lobed; they open in the evening and wilt by the next morning.
By fruit shape, long ones are distinguished as Naga-yugao and round ones as Maru-yugao.

[History]
It is said to be native to North Africa or India.
Its cultivation has a very long history, and it has been excavated from sites in China from the 12th century BC, from sites in Southeast Asia, central to southern Africa, and Egypt.
In Japan too it has been excavated from Jomon period sites.
It appears in The Tale of Genji, The Pillow Book and other works.
Varieties close to those now cultivated came from China during the Tenbun era (1532–55).

[Uses]
Kanpyo (dried gourd strips) is made mainly by peeling the flesh of young Maru-yugao fruits into strips and drying them.
Like the Hyotan, the fruit can also be used as a container, with the flesh and the inner pith removed and the shell dried.

[Cultivation]
It prefers sunny, well-drained, neutral to slightly alkaline soil.
The temperature at which it grows easily is 25–30 °C.
It needs water when the fruits are growing larger, but plants in the ground need no watering unless conditions become very dry.
Overwatering causes excessive leaf growth and can cause disease.
For planting, a ridge width of 1 m and a plant spacing of 70–80 cm are necessary.
Pinch the tip when there are 6–7 true leaves to encourage the growth of side vines.
When the side vines have grown, select and keep 3–4 evenly developed ones.
Rearrange the side vines as appropriate according to the cultivation area.
Diseases develop easily when the vines touch the ground, so once the vines start to grow, spread straw to prevent mud splashing and a rise in soil temperature.
Leave only about 3–4 secondary vines.
When female flowers bloom, pollinate them by hand.
When the fruits reach the size of a baseball, thin them, keeping well-shaped ones, to 1 fruit per branch.
After fruit set, apply additional fertilizer so that nutrients do not run out.
Pests and diseases include anthracnose and aphids.

[Notes]
Varieties not used for food contain a large amount of cucurbitacin, a bitter compound that can also cause food poisoning.
Even among edible varieties, plants with a high cucurbitacin content occasionally appear, so if you notice bitterness, avoid eating it.
The Japanese name was given in contrast to Asagao and Hirugao, because the flowers open in the evening and wilt the next morning.
It is sometimes confused with Yorugao of the Hirugao family, since that plant is also sometimes called Yugao.

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