Common name: Yellow Flag
Iris pseudacorus L. APNI*
Description: Clump-forming evergreen herb 75–160 cm high (usually c. 100 cm); tough rapidly spreading rhizomes on or near soil surface, reddish brown.
Leaves closely and densely set along rhizome, sword-shaped, typically 70–100 cm long, c. 2–3 cm wide, apex acute, surfaces dark green with cross veinlets apparent when held up to light.
Scape terete, with several long leaves, usually branched; cymes 2–5-flowered; spathe bracts ovate, 4–10 cm long. Flowers to c. 12 cm diam. (typically 7–10 cm), yellow with brown or violet veining on the falls (somewhat variable in expression), pedicel 2–5 cm long and stout. Perianth tube c. 1–1.5 cm long, narrow and funnel-shaped; outer lobes (falls) recurved, drooping, lacking beard, broadly ovate rapidly narrowed to basal claw, 5–7.5 cm x 2–3 cm; inner lobes (standards) 2–3 cm x 4–8 mm, shorter and narrower than style branches but more erect. Style branches oblong, crest bifid and fimbriate.
Capsule c. 5 x 2 cm, oblong-elliptic, beaked; seeds brown, somewhat trigonous.
Flowering: Spring in to early summer.
Distribution and occurrence: Reported as somewhat weedy on the North Coast and SW Slopes but almost certainly more widespread. Common in Europe and extending to western Siberia, the Caucasus, Iran, Turkey and North Africa (Mathew 1981).
Grows alongside lakes, dams and waterways.
NSW subdivisions: *NC, *SWS
Text by E.A. Brown (2002); edited KL Wilson (Jan 2014)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.