r f ■ .. -r- 



CLARKE— THE CYPERACEAE OF COSTA RICA. 445 



Lyprolepis deuiulata StoiuL Syn. PI. Glum. 2: 130. 1S55, 

 Distriuttton: TropH'al America tinil Afri<u. 



Costa Rioam o<>Lr.ECTU)Ms: Piu^rto LiiiKui, rUfier 4215; Tlora Banana, Tomluz 

 9122. 



4. Kyllinga pumila Michx. Fl. 1: 28. 1803. 



Kylhnga caespitosa Nees in Mart. Fl. Bras. 2': 12. 1842, excluding Kunth synonym 



and variety fi. 

 Distribution: Common tlirougliout tropical and tcunperato America; frequent in 



Africa. 



Costa Ricax collection's: IIojTtnann 2^1 , 41^7, 4fJ9; rolalcowshj 4, IGO, 409; San 



CarloR, Tondjiz 2h^'?>; Boruca, Tomhn ilS)?>: Talamanca, Tnnditz S747; Rio Tufp, alti- 

 tude GOO meter?, Tonduz 8180; Turrialba, altitude 570 met(TP, Tonduz 82G4; Rio 

 Aqua Caliente, altitude 1,300 meters, Pittur 2403. 



5. Kyllinga odorata Vahl, Enuni. 2: 382, ISOG. ' 

 Kyllimja elongata H. B. K. Nov. Gen. & Sp. 1: 211. 1815. 



Distribution: Very common in Xorth and South America from Louisiana to 



Uruguay. 



Costa Rican collections: Hoffmann 702; Rio San Juan, P iltier 25S0; Greytown; 



Alajuelita, altitude 1,000 meters, Tonduz 8849; San Jose, altitude 1,100 meters, 



Tonduz 434. 



2. PYCREUS Beauv. 



Spikelets 5 to many-flowered; rachilla persistent; two lowest glumes empty, per- 

 sistent; 4 or more next succeeding 2-rank('d, bisexual, perfecting nuts, caducous in 

 fruit from the lowest upwar<!; a few of the Tippermost sterile or vacant, arranged in 

 about 3 spirals; hypogynous bristles none; stamens 1 to 3, anterior; style branches 

 2, on a plane passing through the rachilla; nut laterally compressed. — Plants glabrous. 

 Stems leafy near the base, otherwise naked. Spikelets arranged in spikes, often dense, 



hardly digitate. 



Species 03 distributed to the warmt^r regions of both hemispheres, a few extending 



to within the Temperate Zone. 



KEY TO THE SPECIES. 



Superficial cells of the nut, at least in many, longitudinally oblong; nut transversely 

 and delicately undulate-lineate. (Zoxatae.) 



Annual, tufted, often simply umbellate 1. P. Jlavescens. 



Superficial cells of the nut subquadrate; nut minutely reticu- 

 late, punctulate, or granular. (Reticulatae.) 

 Spikelets straw-colored or brownish-yellow. 



Umbels crowded into a single head 2. P. propinquus. 



Spikes subglobose, commonly umbellate 3. P. helvus. 



Spik(4ets chestnut-brown or variegated with chestnut. 



Annual, spikelets subinflated, arranged in loose spikes. 4. P. lagnnetto. 

 Stems decumbent at base, often cre(^ping; spikelets 

 rigid, forming dense spikes. 



Spikelets 3 mm. wide 5, P. mdanostachyus. 



Spikelets 2 mm. wide 6. P. elcgantulus. 



1. Pycreus flavescens iL.) Beauv.; Reich(mb. Fl. Excurs. 1: 72. 1830-1832. 

 Cy peril s flavesceiis Tj. Sp. PI. 1: 40. 1753. 

 Cyperiis fascindalas Ell. Bot. S. C. & Ga. 1: G3. 181C. 

 Cyperus eUiotianiis Schult. in Roem. & Sehult. Syst. Mant> 2: 100. 1824. 

 Pycreus elUoltianiis Xees, Linnaea 9: 283. 1834. 

 Cyperus durandii Boeck. AUgem. But. Zeitschr. 1: 185. 1895. 



