Leafa Nova

A leaf blade records the climate it grew in. Broad, untoothed, large blades belong to warm wet forests; small, finely toothed ones to cooler or drier places. Leafa Nova is the instrument that turns that relationship back into figures. SCORE THE ASSEMBLAGE Build an assemblage of leaf morphotypes and score each blade on ten physiognomic characters - margin, tooth density, tooth shape, apex, base, blade shape, size class, length-to-width, lobing and texture - choosing every state from an illustrated ladder instead of typing a guess. MEASURE OFF THE PHOTOGRAPH Lay the leaf flat with a printed ruler card beside it, photograph it or bring in a frame you already have, and set the scale with two taps on the card's marks. Four more taps - tip, base and the two widest points - give blade length, width, length-to-width ratio and leaf area class, and a separate pass counts teeth along twenty millimetres. The millimetres-per-pixel figure is stored with the record, so every length stays in real units, and removing a photograph clears the measurements that came off it. THE READ Two classic physiognomic regressions over the whole assemblage at once: leaf-margin analysis for mean annual temperature, leaf-area analysis for mean annual precipitation. Both come back with an error band rather than a bare number, because a small assemblage cannot promise more than that. WHERE IT SITS The assemblage plotted in physiognomic space against eight reference vegetations, with the nearest analogues ranked - and whatever is weakening the read listed in order, each with its correction: too few blades, damaged margins, an incomplete character. THE KIT Ten pieces of collecting and pressing equipment, the eight vegetation calibrations with the figures that define them, and a glossary of every character state. Set your site name, your units, and which calibration set to regress against. IT READS SHAPE, NOT IDENTITY Leafa Nova never names a plant and never identifies a species. It works entirely on the device, offline, with your photographs and records staying where you made them - and it serves a hedgerow you can reach today as well as a tray of pressed or fossil blades.