Green Mars - Kim Stanley Robinson [90]
So the lichen were prospering, and along with the species that Sax could identify, with the help of photos on his wristpad’s little display screen, were many more that seemed not to correspond to any listed species. He was curious enough about these nondescripts to pluck a few samples, to take back and show to Claire and Jessica.
But lichen was only the beginning. On Earth, regions of broken rock newly exposed by retreating ice, or by the growth of young mountains, were called boulder fields, or talus. On Mars the equivalent zone was the regolith— thus effectively the greater part of the surface of the planet. Talus world. On Earth these regions were first colonized by microbacteria and lichen, which, along with chemical weathering, began to break the rock down into a thin immature soil; slowly filling the cracks between rocks. In time there was enough organic material in this matrix to support other kinds of flora, and areas at this stage were called fellfields, fell being Gaelic for stone. It was an accurate name, for stone fields they were, the ground surface studded with rocks, the soil between and under them less than three centimeters thick, supporting a community of small ground-hugging plants.
And now there were fellfields on Mars. Claire and Jessica suggested to Sax that he cross the glacier, and hike downstream along the lateral moraine, and so one morning (slipping away from Phyllis) he did so, and after half an hour’s hiking, stopped on a knee-high boulder. Below him, sloping into the rocky trough next to the glacier, was a wet patch of flat ground, twinkling in the late-morning light. Clearly meltwater ran over it most days— already in the utter stillness of the morning he could hear the drips of little streams under the glacier’s edge, sounding like a choir of tiny wooden chimes. And on this miniature watershed, among the threads of running water, were spots of color, everywhere, leaping out at the eye— flowers. A patch of fellfield, then, with its characteristic millefleur effect, the gray waste peppered with dots of red, blue, yellow, pink, white. . . .
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