PlantKey Open ecological atlas
Planner
Home / Browse / Carex / Fragile Sheath Sedge
Wikimedia Commons — CC, credited & licensed per image
Cyperaceae family

Fragile Sheath Sedge Carex fracta

Native

Fragile Sheath Sedge is a perennial grass native to the lower 48 states. It blooms Jun – Aug.

More about this plant

Carex fracta is a species of sedge known by the common name fragile sheath sedge. It is native to the western United States from Washington to California, where it grows in moist to dry areas in mountain forests and meadows. This sedge produces dense clumps of stems sometimes exceeding a meter tall. The leaves are attached to the stem with a characteristic thin, membranous sheath. The inflorescence is a dense or loose cluster of light green to gold spikes. Some spikes occur lower on the stem as well. The flowers are covered in light colored scales. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 9 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
TRY Plant Trait Database (CC BY 4.0) — Foliage
Lifespan
Perennial
Foliage
Broadleaf
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
derived roles
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Bloom (the flower's colour)
Bloom · Jun – Aug — 260 obs · Herbarium specimens — Park et al. 2023 (CC BY 4.0)
Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~36 caterpillar species

Carex supports ~36 caterpillar species.

Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is a strong genus.

Recorded feeding on Carex in North America, including:

Aletia oxygala · owlet moth Amphipoea americana · American Ear Moth Amphipoea interoceanica · Interoceanic Ear Moth Amphipoea velata · owlet moth Apamea finitima · owlet moth Apamea indocilis · Ignorant Apamea
+ 8 more species →
Biselachista cucullata · grass-miner moth Celaena reniformis · owlet moth Chortodes inquinata · owlet moth Cingilia catenaria · Chain-Dotted Geometer Cosmopterix clemensella · cosmet moth Cosmopterix ebriola · cosmet moth Cosmopterix fernaldella · cosmet moth Ctenucha brunnea · Brown Ctenucha
Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0).
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
How we know this (1) Methods & honest limits
Climate niche (heat tolerance & native rainfall) Derived

We take the plant’s U.S. county range and look up each county’s long-term climate, then summarise: native rainfall = the median annual rainfall across its counties; heat tolerance = the warm end (90th percentile) of average temperature across its range (mirroring how our cold-hardiness floor uses an extreme). Counties + medians blunt the roadside/observer bias that makes point-level climate unreliable. Needs at least five placeable counties.

Honest limits: A realized, sampling-biased niche (where it has been recorded, not its physiological optimum), and county climate is coarse — large Western counties span deserts and mountains. Derived guide, never a measured fact.

Realized-niche / climate-envelope approach (Pearson & Dawson 2003; Soberón 2007). Climate: NOAA NCEI nClimDiv county normals (1991–2020).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (19) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[05] Invasive / introduced status — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[06] Wetland indicator — USACE National Wetland Plant List (2022)
[08] Description — Wikipedia (CC BY-SA)
[09] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[11] Conservation rank — NatureServe Explorer (CC BY)
[13] Functional traits — TRY Plant Trait Database (CC BY 4.0)
[14] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[15] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[17] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[18] Caterpillar species — NHM HOSTS (CC0)
[19] County range — GBIF Open Data — open-licensed occurrences (CC0/CC-BY) → county
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
Cite this page Open data, please attribute

PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).

Citation

Loading…

BibTeX 
Loading…