85 (27) Gramineae 



The character illustrated for each of the common species of grasses is the ligule. This 

 is a membranous or hair structure found where the blade of the leaf joins the sheath 

 (see Plate I). The grasses are arranged below in their typical habitat: 



I. Dunes 



Ammophila breviligulata, Dune, Marram, or 

 Beach Grass 



A very coarse grass characteristic of frontal 

 dunes and hollows. It also occurs at edge of 

 and on the eroded portions of sea cliffs and on 

 beaches. Ligule membranous to 3 mm long. 

 Flowering spike linear, cylindric and completely 

 covered with flowers. 



Figure 90. — Ligule X4. 



Festuca rubra. Red Fescue Grass 



A less coarse grass of the back dunes, sometimes 

 scattered in the Ammophila zone. Sheath brownish 

 and blades stiff and setaceous, ligule membranous. 

 Growing from a creeping rootstock. Less frequent 

 in tidal marsh, in Spartina patens and Juncus gerardi 

 zones. Flowers in a loose panicle. 



Figure 91.— Ligule XIO 



Deschampia flexuosa, Common Hairgrass 



Numerous inward rolled threadlike basal leaves 5-20 cm 

 long, 0.4 mm wide; stem slender and nearly naked of 

 leaves; ligule membranous, 2 mm; flower panicle very 

 loose, nodding with pedicels blackish and threadlike. 

 Plants of the hollow of dunes and top of sea cliffs. 



Figure 92.— Ligule X15. 



37 



