xv, 6 Merrill: Additions to Flora of Guam 541 



A glabrous, erect, apparently tufted perennial grass up to 60 

 cm high. Leaves rather rigid, linear-lanceolate, 15 to 25 cm 

 long, 5 to 8 mm wide, smooth, slenderly acuminate. Inflores- 

 cence exserted, composed of about 15, ascending, somewhat 

 crowded, racemosely arranged spikes 6 to 12 cm in length, the 

 axis of the inflorescence up to 4 cm long. Axis of the spikes 

 about 1 mm wide, the spikelets numerous, oblong to oblong- 

 lanceolate, about 2.5 mm long, alternate, in two rows. First 

 glume obsolete or reduced to an oblong-lanceolate, somewhat 

 hyaline, pilose scale less than 1 mm in length. Second glume 

 somewhat pubescent, 5- or 7-nerved, usually acute, the margins 

 somewhat inflexed over the flowering glume. Flowering glume 

 lanceolate, glabrous, as long as the second empty glume. 



Guam, Cabras Island, Nelson 520 (type) April 24, 1919, near 

 the seashore. The same species is represented by /. Guerrero 

 471, collected on rocks at Anaw Point, July 26, 1916. 



This species manifestly belongs in the small group of Poly- 

 nesian ones discussed by Stapf following his description of 

 Digitaria pacifica which includes D. pacifica Stapf, from Christ- 

 mas Island; D. stenotaphrodes Stapf, which extends from the 

 Caroline Islands to the Paumotu Archipelago; and D. platy- 

 carpha Stapf, from Bonin Islands. These species, as Stapf has 

 indicated, form a well-marked natural group which seems to 

 be peculiar to the Pacific islands. To this group may also be 

 added Digitaria mariannensis Merr., the type of which was also 

 from Cabras Island, Guam, but which differs radically from the 

 other species mentioned above in its entirely different habit; 

 in its small size ; in its paired spikes ; and in being ciliate-pilose. 

 The group is well characterized by its very greatly reduced or 

 obsolete first glume, the spikelets generally consisting of a single 

 empty glume with the flowering glume and its palea. Digitaria 

 robinsonii is well characterized in the group by its numerous 

 spikes. 



CYPERACEAE 



SCLERIA Linnaeus 

 SCLERIA LITHOSPERMA (Linn.) Sw. Prodr. (1788) 18. 



Guam, Nasso River, Nelson 308, March 21, 1918, common 

 along the banks of the river. A common pantropic species not 

 previously recorded from Guam. 



168743 4 



