202 THE POTOMAC OR YOU^IGER MESOZOIO FLORA. 



tical or oblong, acute to acuminate, attached b}* a very short pedicel ; 

 nerves forking near the base, then parallel to near the tips, where tliey are 

 more crowded. 



Localities : Fredericksburg ; road-side near Potomac Run ; fishing 

 hut above Dutch Gap Canal. 



The plant is not uncommon at the Dutch Gap locality, but is com- 

 paratively rare elsewhere. The best specimens (as PI. LXXXVI, Fig. 5) 

 come from Fredericksburg. Fig. 3 of the same plate, having its leaves 

 widest at base and abruptly rounded off there, comes from the Potomac 

 Run locality, and is possibly a different species. PI. LXXXV, Fig. 14, 

 shows a stem of unusual thickness. 



Nageiopsis angustifolia, sp. nov. 



Plate LXXXVI, Figs. 8, 9 ; Plate LXXXVII, Figs. 2-fi ; Plate LXXXVIII. Figs. 1, 3, 4, 6-8 ; Plate' 



LXXXIX, Fig. 2. 



Leafy stems large, branching copiously and wide-spreading ; branches 

 often opposite, swollen at their attachments to the main stem, and marked 

 with scars left by the bud-scales; the leafy stems often subdivided towards 

 their ends into smaller branches on which the leaves are much diminished; 

 leaves varying much in size, very long in proportion to widtli, narrowly 

 linear-acute to acuminate, generally very remotely placed, narrowed grad- 

 ually to apex and base, attached by a short twisted pedicel generally to the 

 sides, sometimes to the upper and lower surfaces of the stems slightly 

 within the margin ; nerves forking near the base and then parallel to the 

 summit, the outer ones terminating in the margin below the summit of 

 the leaves, quite strong. 



Localities: Fishing hut al)ove Dutch Gap Canal; road-side near Poto- 

 mac Run ; 72d mile-post ; bank near Brooke ; Fredericksburg ; near Tel- 

 egraph Station ; Fort Washington. 



This fine species is one of the most widely diffused of the Potomac 

 plants, and is the most generally distributed species of Nagclopsis. It is 

 not very rare at the Dutch Gap locality, but is most common at Freder- 

 icksburg, where the plants given in PI. LXXXVI, Figs. 8, i), and PI. 

 LXXXVII, Fig. 2, occur. It is one of the most noteworthy connecting 



