172 GENERA DUBIA. 
Radix fibrosa, annua. Folia glabra. Spice subglobose, barbate, violaceo. 
Cynosurus esset si calyx multiflorus. ( Charact. genericus ex Desvaux. ) 
SPECIES : 
1. Pterium elegans Desv. — Oriens. 
198. RHYTACHNE Dzsv. 
Spicule biflore, excavationibus rhachis immersa; flores inclusi, inferior her- 
maphroditus, superior masculus. Gluma unica, coriacea, transverse rugosa, aris- 
tata. Pales ovatee , aristatae. Stamina tria. 
Culmus subcespitosus, erectus. Folia involuto-setacea » glaberrima. Spica solita- 
ria, terminalis. ( Character genericus ex Desvaux.) 
SPECIES : 
1. Rhytachne rottboellioides amit. — Antille. 
199. /EGIALINA. Scnurr. 
ZEgialitis 'Trin. 
Panicula subcapitata. Glume/ due, chartaceo - herbacec, equales, ciliata, 
oblongzx , paleas equantes. Palea inferior chartaceo-membranacea , subnavicularis,, 
apice integro mucronata. Squamule collaterales. Rudimentum cylindricum. 
Gramen littorale, annuum , pusillum. ( Character genericus ex 'T'rin. ) 
SPECIES : 
1. ZEgialina tenuis ScAhu/t. ( /Egialitis tenuis Triz.) — Gallia meridionalis. — Phlei species? 
200. XYSTIDIUM Tun. 
Racemus simplex , laxus. Spicule stipite piloso fulta. Glumze paleis multo lon- 
giores, involutz, subulato-setigere. Pales: hyaline , muticee. Fructus cylindricus, 
tectus. ( Character genericus ex 'Trinio.) : 
SPECIES : 
1. Xystidium maritimum Trin. — Insule Philippinze. — Cel. Sprengel ad Perotem raram ducit. 
