372 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
HERBARIUM SPECIMENS: 
Nuevo LrE6n: Monterey, Sierra Madre, Canby 272; Pringle 2051. 
San Luis Potosf: San Luis Potosi, Schaffner 145; Parry & Palmer 935 in 1878; 
by irrigation ditch, Hitchcock 5677. 
Hipaueo: Pachuca, rocky hill, Hitchcock 6738. 
Mexico: Flor de Marfa, calcareous bluffs, Pringle 3243. Amecameca, banks, 
Purpus 1615. Popo Park, edge of woods, Hitchcock 5968. Barranca above 
Santa Fé, Pringle 13627. Federal District, hills, Pringle 9558; edge of field, 
Hitchcock 5913; barranca of Rio Aqueducto, Rose & Painter 8635. 
PuEBLa: Esperanza, rocky hill, Hitchcock 6530. Cholula, Nicolas in 1910. 
Veracruz: Consoquitla, Liebmann 477. Orizaba, Bourgeau 2790; open rocky 
hill, Hitchcock 6368. Jalapa, clay cut, Hitchcock 6599. 
117. ACHYRODES Boehmer in Ludw. Def. Gen. Pl. 420. 1760. 
1. Achyrodes aureum (L.) Kuntze, Rev. Gen. Pl. 2: 758. 1891. GOLDEN-TOP. 
Cynosurus aureus L. Sp. Pl. 73. 1753. 
Lamarckia aurea Moench, Meth. PI. 201. 1794. 
Type locality, southern Europe. 
RanGE: Naturalized in southern California and Lower California. ‘ 
HERBARIUM SPECIMEN FROM MExIco: 
Lower CaLiFoRNIA: Ensenada, Orcutt 1428. 
118. POA L. Sp. Pl. 67. 1753. 
BLUE GRASS. 
KEY TO THE SPECIES, 
Plants annual. 
Panicle pyramidal, open; sheaths smooth................. 1, P. annua. 
Panicle narrow, contracted; sheaths scabrous. ............ 2. P. bigelovii. 
Plants perennial. 
Rhizomes present; lemmas cobwebby at base............. 3. P. pratensis. 
Rhizomes absent. 
Plants dwarf, alpine, only a few centimeters in height; 
blades obtuse, short...........-.-----.-------- 4. P. villaroeli. 
Plants not dwarf, more than 20 cm. high. 
Lemmas cobwebby at base. 
Panicle narrow, almost spike-like............. 5. P. conglomerata. 
Panicle loose, the branches slender and 
spreading. 
Lemmas minutely scaberulous, not villous, 
except for the cobwebby hairs at 
base; panicle purple; spikelets 2 or 
3-flowered..........-----2-2-------- 6. P. orizabensis. 
Lemmas villous on the lower part of the 
keel and marginal nerves; panicle 
green; spikelets 6 to 8-flowered..... 7. P. ruprechtii. 
Lemmas not cobwebby at base. 
Lemmas villous on the keel and marginal 
MN€rveS. ..-....---------222----------- 8. P. fendleriana. 
Lemmas not villous. 
Sheaths glabrous; lemmas glabrous except 
on the keel above..............-. 9. P. albescens. 
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