FEB. 1903. PLANTS YUCATANJE MILLSPAUGH & CHASE. 51 



continuous rachis, forming unilateral spikes, rachilla articulated 

 above the empty glumes and produced behind the palea, bearing i or 

 more, usually awned, empty glumes; outer empty glumes 2, mem- 

 branaceous; floral glume more or less indurated, bearing a single awn. 

 Grain trilateral, free within the fruiting glume. Stamens 3. 



Awns minute petraa. 

 Awns prominent: 



1.5-2 mm., floral glume long ciliate on the keel ciliata. 



8-10 mm., floral glume long ciliate at the summit elegans. 



Chloris petraea Swartz Prod. Veg. Ind. Occ. 25. 

 Eustachys petrcea Desf. 



Inflorescence exserted, of 3-6 spikes, 79 cm. long, 2 mm. wide, 

 with 100-170 crowded ascending spikelets; rachis 3-angled, scabrous; 



internodes-4 mm. long. Spikelets 1x2 

 mm., nearly sessile. First glume 1.3 

 mm., ovate, acute, strigose above, his- 

 pidulous on the keel, second 1.5 mm. 

 broad, strigose above, bidentate, the 

 stout green midrib prolonged into a 

 scabrous upwardly curved awn .5-. 6 

 mm. long; floral glume 1.8 mm., na- 

 viculate, ciliate with stiff tawny hairs 

 on the midrib and margins, strigose at 

 the summit, bidentate and bearing an 

 erect awn .2 mm. long; palea equal in 

 length, broadly oval, scabrous on the 

 nerves; empty glume above floret i, obovate, rounded and strigose at 

 the summit, awnless; the floral glume, palea and empty glume shin- 

 ing chestnut brown. Grain translucent pinkish white, ellipsoid, 

 .45-.5X i.i mm.; in section conoid with concave ventrum. 



Hab. Arid rocky plain south of Progreso, Millspaugh PI. 

 Utowana 1724; island of Holbox, 1886, Gaumer (B).* 



Chloris ciliata Swartz ibid. 



Inflorescence included in the inflated sheaths, or sometimes ex- 

 serted at maturity, of 3-7 purplish spikes, 4-8 cm. long, 4 mm. wide, 

 with 60-120 ascending spikelets; rachis 3-angled, hirsute, internodes 

 i mm. or less. Spikelets 2.5-3x3.5 mm. (including awns), on very 

 short hirsute pedicels. First and second glumes lanceolate, acute, 

 awn-tipped, hispid on the keel, first 1.5 

 mm., second 2.5 mm. long; floral glume 

 2.4 mm., ashy brown, hard and shining, 

 naviculate, i -nerved; bearing a scabrous 

 awn 1.7 mm. long from below the apex, 

 a tuft of stiff hairs at the base and 

 densely ciliate on the keel and margins, 

 except at base and summit, and with stiff 

 white hairs 1-1.5 mm - l n g> scabrous-margined at the summit; palea 

 equal in length, aqute, densely ciliate on the nerves with short brown 



*Biologia Central!- Americana Hemsley. 



