おおえのころ (大狗尾) [Index] [Back]

Setaria x pycnocoma

Setaria x pycnocoma

Setaria x pycnocoma

Setaria x pycnocoma

Setaria x pycnocoma

Setaria x pycnocoma

Setaria x pycnocoma

わが国の各地に分布しています。「あわ(粟)」と「えのころぐさ(狗尾草)」との自然雑種とされていますが、「えのころぐさ」の自然状態の変異の中から生まれたという、考えもあります。畑や道ばたに生え、稈の高さは1〜1.2メートルほどになります。8月から11月ごろ、花穂をだします。花穂は長さ7〜24センチ、幅1.5〜2.5センチで、「えのころぐさ」より大きく、花序が枝分かれしています。小穂は長さ2.5〜3ミリとやや大きく、成熟しても緑色が残ります。大形に発育した花穂は、「こあわ」との区別が見た目では困難だといいます。別名で「おおえのころぐさ(大狗尾草)」とも呼ばれます。 
イネ科エノコログサ属の一年草で、学名は Setaria x pycnocoma。英名は Giant green bristle grass。 
The Giant green bristle grass (Setaria x pycnocoma) belongs to Poaceae (the Grass family). It is an annual herb that is distributed all over Japan. It is said to be a natural hybrid between "foxtail millet" and "green bristle grass", but there is also the idea that it was born from a variation in the natural state of "green bristle grass". This grass grows in fields and roadsides, and the height of the culm is about 1-1.2 meters. The flower spikes are borne from August to November. They are 7-24 cm long and 1.5-2.5 cm wide, larger than "green bristle grass", and the inflorescences are branched. The spikelets are slightly large, 2.5-3 mm in length, and remain green even when they mature. It is said that it is difficult to visually distinguish the large-sized flower spikes from "German millet" (Setaria itarika var.germanicum). 
宮城県仙台市宮城野区「仙台うみの杜水族館」にて、2021年06月28日撮影。 

Shu Suehiro
shu@botanic.jp