A MOUNT WASHINGTON SANDWORT. 595 



ment of the American upland vegetation — an element intrusive from 

 the southern mountains rather than from the circumpolar and northern 

 plains. For the avens is, in fact, a New England mountain variation 

 on a pretty plant which covers the higher Carolina hills — Genm radi- 

 atum of Michaux, a hairier representative of the self-same type. The 

 more northern outlier, known as the variety Pechii of Pursh, has 

 smoother leaves and somewhat glabrous stems, but otherwise keeps up 

 the general characteristics of its Southern congeners. Just so, on the 

 slides above the Notch of the White Mountains, not far from the 

 "Willey House, I found in profusion another essentially Southern plant 

 — the Paronychia argyrocoma, a silvery looking whitlow-wort, whose 

 inconspicuous blossoms, allied to those of our European knarvel, are 

 yet rendered beautiful and noticeable to mountain insects by their 

 numerous thin and shining scai'ious bracts. This curious plant, one 

 of the most suggestive I found in America, is not known to occur 

 anywhere else in the far Northern States save in this one deep and 

 secluded valley. But, among the Alleghanies, it occupies every breezy 

 summit from Virginia southward, so that it belongs, like the Mount 

 Washington avens, to the sub-tropical mountain flora, and only makes 

 its appearance, as if by accident, among the glacial vegetation of the 

 New Hampshire hills. 



How did these isolated Southern species come to obtain a footing 

 in such bleak situations near the northern limit of the United States ? 

 Doubtless, in the first instance, their introduction was due to the 

 agency of casual birds, who must have brought the seeds with them, 

 clinging to their feet or legs, on their annual migration from their 

 winter dwelling-places. Once fairly started on the New Hampshire 

 mountains, they succeeded well because naturally adapted to their 

 new situation, where the summer heat would not be far inferior to 

 that of their native Carolinian heights, while the snow -sheet of 

 winter would amply protect them from the killing effects of Decem- 

 ber frosts. 



And this brings us back once more to the point from which we 

 started — the history of our little Mount Washington sandwort. Noth- 

 ing was more noticeable, as we mounted the slopes on the cog-wheel 

 railway, than the wide sheets of conspicuous blossom that greeted us 

 everywhere with their striking mass. First of all, it was Canadian 

 cornel in broad patches that whitened the soil ; then it was great 

 areas of the Greenland sandwort ; and then golden spaces of the yel- 

 low avens. Now, all the world over, mountain-plants, especially those 

 that grow beyond the limit of trees, and close up to the very snow- 

 line, are celebrated for their exceptional display of vivid color. 

 Everybody must at least have heard of the Alpine gentians, globe- 

 flowers, and daffodils, that belt with blue or gold or primrose whole 

 zones of mountain-side in Swiss spring-time. Exactly the same thing 

 is true of the arctic flowers ; short as is their summer, they make it 



