Northern Wildrice Zizania palustris

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.

A small, hand-checked crosswalk: each native edible is matched to its food in the USDA nutrient database (e.g. American persimmon → "Persimmons, native, raw", black walnut → "walnuts, black"), and we read that food’s per-100 g values. We only include matches that are unambiguous; a few genus-level commodities (e.g. mulberries) are marked as the closest food match. We do NOT auto-match by name (too error-prone) — so coverage is deliberately small.

Honest limits: Composition of the edible part as a food (often the cultivated/commodity form), matched by common food name — a guide, not a measurement of the exact wild plant. Never an identification or edibility guarantee.