Bidens pilosa var. minor × Bidens pilosa var. pilosa
Bidens pilosa var. minor × Bidens pilosa var. pilosa("Ainokosendangusa")
Japanese name: アイノコセンダングサ Scientific name:Bidens pilosa var. minor × Bidens pilosa var. pilosa
[Overview]
An annual about 50–110 cm tall, found along roadsides and in vacant lots.
It is considered a hybrid between Koshirono-sendangusa and Kosendangusa.
The stem is erect and branched, with 4–6 ridges and short hairs.
The leaves are opposite on the lower part of the stem and alternate on the upper part, pinnately compound, 10–14 cm long, with 3–5 leaflets.
Some leaves on the upper part of the stem are not pinnately compound but are 3-lobed or lanceolate simple leaves.
The leaf margins are serrated.
Flower heads are borne at the tips of branches on the upper part of the stem; there are no ray florets, but some of the outer tubular florets look like white ray florets.
The size of these tubular florets varies from very small and inconspicuous to a form close to that of Koshirono-sendangusa.
The outer involucral bracts are spoon-shaped with expanded tips, numbering 7–8.
The fruit is an achene with 2–4 awns (spines).
The awns have small downward-pointing barbs.
[Notes]
Some views include it within Kosendangusa.
