HERBACEOUS PLANTS OF THE MIDDLE DUNES. 



377 



uncommon. A reduced form of the annual Krigeron canadensis, some- 

 times only 5 lit 8 centimeters (-2 or 3 inches) high, and with thicker 

 leaves than in other situations, is especially abundant in rather moist 

 sand. Lec7iea marUima and Hudson ia fomentosa (both perennial and 

 suffrutescent) usually grow together, I ml the latter often covers small 

 areas unassociated with other species (fig. 09). A small Cyperus with 

 hard tubers, C. grayi, and two or three species of Panieum (P. scrib- 

 7ierianMti, P. angustifolium) often grow with these Cistaceae, the first, 

 however, sometimes in pure associations. Phaseolus kelvolus, with 

 long, radiant, prostrate stems, is occasional in open places. 



Monarda punctata is abundant, particularly at the edge of the 



Via. tiO. — Hiidsunia tumeiitusa on tlio dunes near Virginia Beach (I'iuus taeda in background). 



Myrica thickets, where ( '< iidi rus tribuloides macrocephaliis, a canes- 

 cent form of Sohuiiuii nigrum, and Plajsnlis viscosa^ are most at 

 home, tn the shelter of the hushes of Myrica carol inensis a number 

 of species occur which do tiol properly belong to the dune flora and 

 are not especially adapted to thai environment. Such are Phytolacca, 

 decandra, typical Eriyeron canadt nsis, TUupatoriuwi cfipUli folium 

 (foenicidaceum), and Clienojjodium anthelminticum, tin 1 last, how- 

 ever, not rarely occurring away from the shade and protection of the 

 thickets. These; plants wilt much more rapidly when uprooted than 

 do most of the true dune plants. 



1 This plant, which was seen in Virginia only ;it Cape Henry, is common along 

 the North Carolina coast. 



