Dodder vine - Dodder vine

An annual vine in the Convolvulaceae family (APG classification: Convolvulaceae). It parasitizes various plants such as Japanese knotweed, kudzu, and mugwort. After growing above ground, it extends its vines to wrap around the host, inserting its parasitic roots into the host's vascular bundle, where it loses its roots and grows by absorbing nutrients from the host. The vines are yellowish brown and have scaly leaves. Small white flowers bloom in spikes from August to October. The corolla is bell-shaped with five lobes and one style. It grows in clusters in riverbeds and fields in hilly and mountainous areas, and is distributed throughout Japan, the Korean peninsula, China, and the Amur region. In traditional Chinese medicine, the seeds are called "tosishi" and are used medicinally.

There are about 200 species in the Cuscuta genus worldwide, and five in Japan, including some that have become naturalized. These parasitic plants belong to the Cuscutinae subfamily, but some consider it to be an independent family, Cuscutaceae.

[Hideo Takahashi June 21, 2021]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

ヒルガオ科（APG分類：ヒルガオ科）の一年生つる草。イタドリ、クズ、ヨモギなどさまざまな植物に寄生する。地上に生えたあと、つるを伸ばして寄主に巻きつき、寄生根を寄主の維管束に挿しこむと根を失って寄主から養分を摂取し、成長する。つるは黄褐色、鱗片(りんぺん)葉がある。8～10月、小さな白色花を穂状に集めて開く。花冠は鐘形で5裂し、花柱は1本。丘陵から山地の川原や野原に群生し、日本全土、および朝鮮半島、中国、アムール地方に分布する。漢方で種子を「菟糸子(としし)」と称し、薬用とする。

　ネナシカズラ属は世界に約200種、日本には帰化したものも含め5種分布する。寄生生活をする植物で、ネナシカズラ亜科に属すが、ネナシカズラ科Cuscutaceaeとして独立させる考えもある。

［高橋秀男　2021年6月21日］

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