Iris lacustris Nutt.
  • Gen. N. Amer. Pl.
  • Dwarf lake iris

Cite taxon page as 'WFO (2021): Iris lacustris Nutt. Published on the Internet; Accessed on: 11 Apr 2021'

General Information

Rhizomes with proximal cordlike portion 0.8–2 dm × 2 mm, bearing brown, scalelike leaves and rarely roots, distal portion enlarging to 3–5 × 0.8–1.2 cm, producing fibrous roots, 2–3 brown, sheathing, bractlike leaves, then 8–12 green foliage leaves; usually 2 cordlike rhizomes produced from apex as new growth begins in spring. Stems simple, 0.8–4 cm. Leaves: basal with blade broadly linear at anthesis, slightly falcate, 4–6 cm × 6–8 mm, enlarging to 16 cm × 10 mm; cauline with proximal 1–2 resembling basal leaves, 4–6 cm, distal 2 more sheathing of stem, exceeding spathes. Inflorescence units 1(–2)-flowered; spathes green, outer closely sheathing inner and enclosing ovary, slightly keeled at midrib, 4.5 cm, ± equal, margins scarious. Flowers: perianth sky blue; floral tube dull yellow, funnelform, 1–2 cm, dilated upward to 4–5 mm diam.; sepals 2–2.3 × 0.8 cm, tapering gradually into claw, apex emarginate, signal white with deep violet margin, with 3 yellow and white, toothed, low ridges; petals spreading, narrowly oblanceolate, 1–1.5 × 0.4–0.5 cm, shorter and narrower than sepals, apex emarginate; ovary sharply trigonal, 0.8–1 cm; style 1–2 cm, crests linear to semiovate, 4 mm, margins crenate; stigmas rounded, margins entire; pedicel 0.6–1.5 cm. Capsules roundly triangular, 1.2 × 8 mm, enclosed in spathes. Seeds dark brown, with white appendage spiraled around seed, ca. 3 mm, quickly drying when exposed to air. 2n = 32, 42.

  • Provided by: [A].Flora of North America @
    • Source: [
    • 1
    • ]. 

    "Like a smaller form of no. 2 [Iris cristata Aiton]; lvs broadly linear, curved- arching, 4–6 cm at anthesis, later to 18 cm × 5–10 mm; spathe-valves closely sheathing each other, the upper and lower equally spaced; perianth-tube dull yellow, 1–2 cm, dilated upwards, not or scarcely exceeding the spathe-valves and shorter than the sep and pet; fls 5–6 cm wide, the pet emarginate; seeds dark brown, arillate; 2n=42. Gravelly shores and cliffs in calcareous soil around lakes Michigan and Huron; now rare. May."

  • Provided by: [E].New York Botanical Garden
    • Source: [
    • 2
    • ]. 

    Other Local Names

    Dwarf lake iris


     Information From

    Flora of North America @
    'Flora of North America @ eFloras (2008). Published on the Internet [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • A Flora of North America Association
    International Union for Conservation of Nature v.3
    IUCN 2019. The IUCN Red List of Threatened Species. Version 2019-1.
    • B See IUCN Terms and conditions of use
    International Union for Conservation of Nature
    IUCN 2016. IUCN Red List of Threatened Species. Version 2016-2
    • C All Rights Reserved
    World Flora Online Data. 2017.
    • D CC0 1.0 Universal (CC0 1.0).
    New York Botanical Garden
    Descriptions of plants should be attributed to the full citation for each individual article, chapter or book that is the source for each record, which should include the authors of original publication.
    • E Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
    World Flora Online consortium
    World Flora Online Data. 2018.
    • F CC0 1.0 Universal (CC0 1.0).