Cyperus iria — rice-field flatsedge

Characteristics

• Flowers

  Anther length

  0.2–0.4 mm

  Floral bristle color

  NA

  Floral bristle number

  0

  Floral bristle relative length

  NA

  Floral bristles

  NA

  Floral scale hairs

  there are no hairs on the floral scales

  Floral scale length

  1.3–1.8 mm

  Floral scale nerves

  2-5

  Floral scale shape

  • the floral scales are obovate (roughly egg-shaped, but with the widest part above the middle)
  • the floral scales are orbicular (circular in outline)

  Floral scale translucent

  the floral scales are opaque

  Flower number per cluster

  • 5-20
  • more than 20

  Inflorescence bract angle

  the bracts are vertical or angled only slightly outwards

  Inflorescence bract number

  there are two to five bracts per inflorescence

  Inflorescence bract position (Sparganium)

  NA

  Inflorescence bracts

  there are at least two bracts, and they are either flat or folded or rolled in at the edges

  Inflorescence branching

  the inflorescence is branched

  Inflorescence crowding

  the inflorescence is at least somewhat spread out, with at least one branch coming from the main stem

  Inflorescence position

  the inflorescence is at the tip of the plant

  Inflorescence shape

  the aggregations within the inflorescence are at least somewhat flattened in cross-section

  Inflorescence type

  there are two or more flowers, spikes or flower clusters on a branched inflorescence

  Perianth composition

  there is no perianth on the plant

  Stamen number

  • 2
  • 3

  Stigma number

  3

  Style division

  the top two thirds of the style is divided

  floral bristle barbs

  NA

  plantlets budding at flower bases

  no

• Fruits or seeds

  Achene surface texture

  the achene has very tiny pits or depressions on it

  Achene tubercle relative width

  NA

  Achene tubercle width

  0 mm

  Capsule relative length

  NA

  Fruit cross-section

  the fruit is triangular to terete (circular) in cross-section

  Fruit length

  1.2–1.4 mm

  Fruit type (general)

  the fruit is like a seed, and surrounded by scales

  Fruit type (specific)

  the fruit is an achene (dry, seed-like fruit) without a tubercle (a swelling or projection, usually of a different color or texture)

  Locules in capsule

  NA

  Seed length

  0 mm

  Seed tail relative length

  0 mm

  Seed tails

  NA

  Tubercle height

  0 mm

• Growth form

  Lifespan

  the plant lives only a single year or less

  Underground organs

  there are only slender roots on the plant

• Leaves

  Auricle length

  0 mm

  Auricle texture

  NA

  Auricles

  there are no auricles on the leaf sheath

  Leaf blade cross-section

  the leaf blade is flat or rolled in at the edges

  Leaf blade length

  150–400 mm

  Leaf blade width

  3–6 mm

  Leaf form

  all the leaves hold their form out of water

  Leaf position on plant

  the attachment points of all the leaves are at or near the base of the plant

  Leaf septa

  the leaf blades do not have transverse septa

  Leaf sheath hairs

  the leaf sheathes are without hairs

  Pedicel length (Typha)

  0 mm

  Stem leaf blade ligules

  there are no ligules at the leaf blade bases

  Stem leaf blades

  there are fully-developed leaves with leaf blades on the main stem

  Width of seed-producing inflorescence

  3–12 mm

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Massachusetts

  Specific habitat

  • man-made or disturbed habitats
  • meadows or fields

• Stem, shoot, branch

  Plant height

  5–60 cm

  Stem shape in cross-section

  the stem is roughly triangular in cross-section

  Stem texture near tip

  the stem feels smooth near the tip

Wetland status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

In New England

From Flora Novae Angliae dichotomous key