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Species
Iris pseudacorus L.
IUCN
NCBI
EOL Text
More info for the term: capsule
This description covers characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available (e.g., [15,21,22,25,28,29,51,56,62,69,88,92,97]).
Aboveground description: The few to several leaves of pale-yellow iris are stiff and erect [21], linear, and 10 to 35 inches (25-90 cm) long [92]. Single or multiple flowering stems are 20 to 39 inches (50-100 cm) tall, usually shorter than or equaling leaves [21]. Plants take 3 years to mature before flowering (review by [35]). Flowers are bright yellow or cream-colored and 3 to 4 inches (7-9 cm) wide [21]. Pale-yellow iris fruits are 6-angled capsules, 2 to 4 inches (5-9 cm) long [21]. The dark brown, smooth, disk-like seeds are closely packed into 3 rows within the capsule (review by [73]). Seeds have a hard seed coat beneath which there is a gas space, allowing seeds to float in water [11].
Belowground description: Pale-yellow iris has rhizomes that are 0.4 to 2 inches (1-4 cm) in diameter (reviews by [73,90]). Pale-yellow iris invests heavily in root development, particularly as a young plant, allowing it to establish in habitats with fluctuating water levels [93]. Roots are usually 4 to 8 inches (10-20 cm) long but can be up to 12 inches (30 cm) long (review by [73]).
More info for the term: fresh
Pale-yellow iris germination is best in moist [11,77] but not waterlogged [42,77] conditions. One review suggests that pale-yellow iris germination may be more dependent on temperature than light [78]. In the field, pale-yellow iris germination in its native range is said to be poor due to fat-like substances present on the inner seed coat. Seedlings were rare in most habitats (review by [73]). However, one author states that a "large number" of pale-yellow iris seeds in Great Britain germinate and put out roots [93]. In Montana, one author suggests that pale-yellow iris germination rates were high based on the high number of seedlings observed in the field and from observations of field-collected seed [54].
In the laboratory, only 25% of fresh-collected seeds from the Netherlands germinated in drained soil in 6 weeks [11]. Germination rates for nonscarified seeds in Great Britain varied from 48% after 15 days to 40% after 12 months (review by [73]). Fresh seed collected from established plants in northern Florida exhibited a germination rate of 62% (Jacono and Ramsey unpublished data cited in [52]). Fall-collected seed from the Theodore Roosevelt Island in the Potomac River had a germination rate of 33% after 97 days of inundated conditions and 90 days of moist conditions [77].
Scarification improves pale-yellow iris germination ([11,26], review by [73]). In a laboratory study in northern England, scarified pale-yellow iris seeds germinated at a significantly higher rate than those that were not scarified (70% versus 48%) (P<0.01) [26]. In laboratory studies in the United States, pale-yellow iris seeds that had their "caps" removed and were placed in water experienced much higher germination; in 30 days, 97% of seeds with caps removed had germinated, while no seeds with intact caps germinated in this time period [13].
Common and widespread (3).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/yellow-iris/iris-pseudacorus/ |
More info for the term: fen
It is not clear how long pale-yellow iris seeds persist in the soil seed bank. Pale-yellow iris was abundant in a wet meadow in northeastern France but was absent from the soil seed bank [86]. Though present at 84% of the quaking fen locations sampled in the Netherlands, pale-yellow iris germinated from only 25% of the seed bank samples. Similarly, though present at 50% of floating forest locations sampled, pale-yellow iris germinated from only 14% of the seed bank samples [84]. Pale-yellow iris seedlings emerged from soil samples taken from tidal freshwater marshes along the Delaware River in New Jersey [41].
Population
Population Trend
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/163999 |
Rhizomes pink, freely branching, producing extensive clumps, 2–3 cm diam., with fibrous remains of old leaves; roots fleshy. Stems usually 1-branched, solid, 7–15 dm. Leaves: basal deciduous, at first erect, then recurved, blade dark green, with prominent median thickening, 4–10 dm × 2–3 cm, slightly glaucous basally; cauline equaling inflorescence unit. Inflorescence units 4–12-flowered; spathes green with brown margins, outer spathe strongly keeled, inner without keel, 6–9 cm, subequal, margins not scarious. Flowers: perianth bright yellow; floral tube 0.6–0.8 cm, with no constriction into ovary; sepals bright yellow or cream colored, lanceolate to ovate or suborbiculate, 5–7.5 × 3–4 cm, base abruptly attenuate, claw ca. 1/2 length of limb, signal a darker yellow basal patch limited by short, brown lines; petals without veining, lanceolate to spatulate, 2–3 cm; ovary triangular in cross section with concave sides and narrow groove at each angle, 1.5 cm; style keeled, 3–4 cm, crests spreading, 1–1.2 cm, laciniate at apex; stigmas rounded with prominent tongue; pedicel 2.5–7 cm. Capsules prismatic to oblong-ovoid, obscurely 3-angled with obvious groove at each angle, 3.5–6 cm, beak 5 mm. Seeds D-shaped, flattened, 6–7 mm, corky, lustrous. 2n = 34.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200028201 |
Major Threats
There are no known past, ongoing or future threats to this species.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/163999 |
Habitat and Ecology
Systems
- Freshwater
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/163999 |