This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...which enable the plant to withstand the extreme conditions of its environment. To these might be added a sixth requisite, the persistence of the subaerial parts during the winter. In every dune region there are some plants which fulfil all or some of these requirements, and which are responsible for the construction of ...
Read More
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...which enable the plant to withstand the extreme conditions of its environment. To these might be added a sixth requisite, the persistence of the subaerial parts during the winter. In every dune region there are some plants which fulfil all or some of these requirements, and which are responsible for the construction of the local dunes. In Illinois the principal ones are Rhus canadensis, var. illinoensis, Ceanothus ovatus, Panicum virgatum, and Tephrosia virginiana. These are discussed in the order of their effectiveness. Tephrosia virginiana (Pl. IX, Fig. 1) is a perennial herb with very long, slender, tough roots. Several stems, each 1-1.5 feet (3-4 dm.) high, arise from a common base and are densely covered by leaves. These serve to catch the sand and hold it during the summer, but they die in autumn and the dead stems are soon removed by the winter storms. The sand is then held by the subterranean root system only. Tephrosia endures covering by sand if it is not to too great a depth, at least not exceeding half the height of the stems. It does not possess the power of unlimited growth during the season, and is consequently not able to keep above the sand indefinitely. Neither is it a very efficient sand-binder, and it dies if the crown and a few inches of the roots are exposed (Pl. IX, Fig. 2). Such cases are seldom seen, because the dead remains are soon blown away. From both of these reasons it is clear that Tephrosia is not a very efficient dune-former, and this is fully substantiated by field observation. Tephrosia dunes are low and gently sloping (Pl. VII, Fig. 2), and are found mainly on blowouts where the rate of sand movement is apparently very slow. This, of course, does not prohibit the plant from growing on larger dunes in company with other s...
Read Less
Choose your shipping method in Checkout. Costs may vary based on destination.
Seller's Description:
10.5 x 7, softcover, pp 23-174, 20 plates, bib, library stamps to front wrapper, soiling to wrappers, tape repaired and separating, corners bumped, good, sound, FIRST ED.
