The flowers were mounted on little mossy cushions or florettes, or tucked among hairy leaves. All the plants hugged the dark ground, which would be markedly warmer than the air above it; nothing but grass blades stuck higher than a few centimeters off the soil. He tiptoed carefully from rock to rock, unwilling to step on even a single plant. He knelt on the gravel to inspect some of the little growths, the magnifying lenses on his faceplate at their highest power. Glowing vividly in the morning light were the classic fellfield organisms: moss campion, with its rings of tiny pink flowers on dark green pads; a phlox cushion; five-centimeter sprigs of bluegrass, like glass in the light, using the phlox taproot to anchor its own delicate roots . . . there was a magenta alpine primrose, with its yellow eye and its deep green leaves, which formed narrow troughs to channel water down into the rosette. Many of the leaves of these plants were hairy. There was an intensely blue forget-me-not, the petals so suffused with warming anthocyanins that they were nearly purple— the color that the Martian sky would achieve at around 230 millibars, according to Sax’s calculations on the drive to Arena. It was surprising there was no name for that color, it was so distinctive. Perhaps that was cyanic blue.

The morning passed as he moved very slowly from plant to plant, using his wristpad’s field guide to identify sandwort, buckwheat, pussypaws, dwarf lupines, dwarf clovers, and his namesake, saxifrage. Rock breaker. He had never seen one in the wild before, and he spent a long time looking at the first one he found: arctic saxifrage, Saxifraga hirculus, tiny branches covered with long leaves, ending in small pale blue flowers.

As with the lichens, there were many plants that he couldn’t identify; they exhibited features from different species, even genuses, or else they were completely nondescript, their features an odd melange of features from exotic biospheres, some looking like underwater growths, or new kinds of cacti. Engineered species, presumably, although it was surprising these weren’t listed in the guide. Mutants, perhaps. Ah but there, where a wide crack had collected a deeper layer of humus and tiny rivulet, was a clump of kobresia. Kobresia and the other sedges grew where it was wet, and their extremely absorbent turf chemically altered the soil under it quite rapidly, performing important work in the slow transition from fellfield to alpine meadow. Now that he had spotted it he could see minuscule watercourses marked by their population of sedges, running down through the rocks. Kneeling on a thinsulate pad, Sax clicked off his magnifying glasses and looked around, and as low as he was, he could suddenly see a whole series of little fellfields, scattered on the slope of the moraine like patches of Persian carpet, shredded by the passing ice.

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