

Looseflower Alpine Sedge Carex rariflora
Looseflower Alpine Sedge is a perennial grass native to Alaska, Canada, and Greenland. It grows to 2.1 ft.
More about this plant
Carex rariflora, the looseflower alpine sedge, is a species of plant in the sedge family. It is found in the United States in Alaska and Maine, and in Canada in New Brunswick and Nova Scotia. In these regions, it is ranked as an obligate hydrophyte in establishing wetland areas. It prefers wet environments such as open bogs, meadows, seepage slopes, and low-elevation heath tundra. This perennial grass, which can be up to 3 feet tall, has fibrous roots, and holds all perennial organs underground. The leaves are alternate, long, narrow, and simple, with parallel veins. They grow in dense clusters, and the dead leaves are found at the base of the plant. The plant blooms and fruits in the summer. All flowers are monoecious and unisexual, producing a spike inflorescence. All inflorescences are subtended by shorter, proximal bracts. Wikipedia →
Growing & care
USDA PLANTS · TRY- Hardiness
- ≥ zone 7 derived from its U.S. range
- Height
- 2.1 ft
- Lifespan
- Perennial
- Foliage
- Broadleaf
- Flower colour
- Brown AI AI image-analysis of community-science photos — lower-confidence (a more subjective call, often an inconspicuous flower); not a botanical record
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:
+ 8 more species → ↑ show fewer
Across 24 U.S. vegetation-survey plots that recorded Looseflower Alpine Sedge, these catalog species turned up most often in the same plot — a real field co-occurrence signal, not a planting prescription.
How we know this (4) Methods & honest limits
We read each species’ measured specific leaf area (leaf area per unit dry weight) from the Global Spectrum dataset and band it: thin & fast (high SLA), medium, or thick & tough (low SLA). The global median is about 10 mm²/mg.
Honest limits: A species-mean from pooled measurements — individual plants vary with light and site. A broad strategy signal, not a precise per-plant figure.
A recorded categorical fact: each species is tagged C3 (standard), C4 (heat/water-efficient) or CAM (succulent, night-time CO₂ uptake) — or a facultative combination. We only show a trait card for the noteworthy C4/CAM cases; C3 is the unremarkable majority, kept in the data but not surfaced as a card.
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.
McKenzie et al. assigned each species a flower colour with a GPT-4V vision model over iNaturalist photos. We use the confident tier plus a separately-labelled lower-confidence top-up (mostly inconspicuous green/brown flowers), and render it as a small tint — never as an asserted fact, and kept out of the written synopsis.
Honest limits: AI image inference (~87% expert agreement on the confident tier); a decorative, confidence-tiered indicator, not a measured trait.
Sources for this entry (23) Open & cited
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).
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