ダイサギソウの花は鷺草に似ているものの、白色の側萼片、唇弁の側裂片が左右に大きく張り出して、風格のある大鷺が舞うように見えます。
The flowers of the Large Egret Orchid resemble those of Habenaria radiata, but differ in that the white lateral sepals and lateral lobes of the lip palp flare out to the sides. This gives the appearance of a stately Great Egret flying through the air.
【仮名】ダイサギソウ
【和名】大鷺草
【英名】Large Egret Orchid
【学名】Habenaria dentata
【誕生】08/ 13, 08/ 21
【開花】08, 09, 10月
【花色】White
ダイサギソウ
ダイサギソウの概要
ダイサギソウはラン科ミズトンボ属の多年草。日本では本州の関東以南、四国、九州、国外では台湾、中国南部、東南アジアに分布しています。陽当たりがよく、湿った草地で自生。花は白色の側萼片、唇弁の側裂片が左右に大きく張り出して、風格のある大鷺が舞うように見えます。
ダイサギソウの名前
ダイサギソウの名前の由来は大きな白鷺「大鷺」のような花が咲くから。または、小鷺のような花が咲く「鷺草」よりも草丈や花が大きいからです。ラテン語の属名ハベナリアは「手綱」という意味で、花の距に由来。種小名デンタタは「歯状」という意味で、唇弁の縁に由来します。
ダイサギソウの姿形
ダイサギソウは卵形～紡錘形の塊茎で越冬。葉は互生の披針形で茎を抱きます。花は外花被が背萼片１枚、側萼片２枚、内花被が側花弁２枚、唇弁１枚。唇弁は３裂で、大きな側裂片に鋸歯があり、細長い距が後方に伸びます。花後は蒴果を形成。熟すと縦に裂けて種子を散らします。
ダイサギソウの近縁
ダイサギソウの近縁種「鷺草」は、姿形が似ているものの、草丈が小さく、開花が７～８月と早め。花は優美な小鷺が翼を広げているように見えます。左右の側花弁は小さな兜状、唇弁の側裂片は細かく裂けた扇状。種小名ラディアータは「放射状」という意味で、側裂片を表します。
Large Egret Orchid
The Large Egret Orchid is a perennial plant of the Orchidaceae family. It is found in Japan south of the Kanto region of Honshu, Shikoku, and Kyushu, and overseas in Taiwan, southern China, and Southeast Asia. It grows naturally in sunny, moist grasslands. The white lateral sepals and lateral lobes of the lip palp flare out to the sides, giving the flowers the appearance of a stately Great Egret flying through the air.
The Japanese name for the Large Egret Orchid means “Great Egret” because of its flowers’ shape resembling a Great Egret. The Latin genus name, Habenaria, means “reins” and is derived from the flower’s spur. The specific name, dentata, means “tooth-like” and refers to the edge of the lip.
Large Egret Orchid overwinters on ovate to spindle-shaped tubers. The leaves are alternate, lanceolate, and clasp the stem. The outer flower has one dorsal sepal and two lateral sepals, while the inner flower has two lateral petals and one lip. The lip is three-lobed, with serrated edges on the large lateral lobes. A slender spur extends posteriorly. After flowering, a capsule forms, which splits lengthwise when ripe, scattering the seeds.
Habenaria radiata, a closely related species to the Large Egret Orchid, is similar in appearance but shorter and blooms earlier, from July to August. The flowers resemble a graceful heron spreading its wings. The left and right lateral petals are small, helmet-shaped, and the lateral lobes of the lip are finely divided, fan-shaped. The specific name means “radiate” and refers to the side lobes.
