HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



41 



plants with papillose-hispid sheaths and blades and contracted panicles; the spikelets 

 are 2.8 mm. long. 



Panicum fasciculatum c[h]arthaginense Doell in Mart. Fl. Bras. 2 2 : 205. 1877. Based 

 on P. chartaginense Swartz. 



Panicum fasciculatum reticulatum Beal, Grasses N. Amer. 2: 117. 1896. Based on 

 P. reticulatum Torr. 



Panicum fuscum reticulatum Scribn. & Merr- 

 U. S. Dept. Agr. Div. Agrost. Circ. 32: 4. 1901. 

 Based on P. reticulatum Torr. The specimen 

 here referred to P. chartaginense is P. ramo- 

 sum L.« of Asia. 



DESCRIPTION. 



Differing from P. fasciculatum in having 



smaller, more compact panicles, the branches 



ascending or appressed, narrower blades, 



usually pubescent on both surfaces, and 



spikelets 2.6 to 3 mm. long. 



There are many intermediate specimens. The well-marked form is usually smaller, 



with appressed branches and blades. It occurs in the drier regions of the Mexican 



Plateau. Some specimens, such as Griffiths 1545 and 1616, cited under P. fuscum 



reticulatum by Scribner and Merrill, & are nearly glabrous. 



The following specimens from Texas seem to be intermediate between the species 

 and subspecies. They are mostly large plants with rather open panicles and spikelets 

 about 3 mm. long: Fort Worth, Tracy 8171; Dona, Tracy 8890; College Station, Price 

 in 1895; Abilene, Bentley in 1899; Victoria, Plank 74; San Antonio, Havard, Heller 

 1698, Jermy 202; Dallas, Reverchon 94; Houston, Thurow 16. 



A closely allied species, P. multiculmum Anders., c from the Galapagos Islands, has 

 been referred to P. chartaginense Swartz by Grisebach.^ 



Fig. 21.- 



■P. fasciculatum chartaginense. 

 type specimen. 



From 



DISTRIBUTION. 



Prairies, fields, and waste ground, Texas and Arizona to Mexico; also in Venezuela 

 (Swartz). 



Texas: Uvalde, Reverchon 1086; Dallas, Bush 1157; Taylor, Ball in 1901; Abi- 

 lene, Bentley in 1899; Waco, Plank 11; Big Springs, Tracy 8289; Columbia, 



Bush 270; Manor, Hall 825; 



San Antonio, Havard in 1882, 



Hitchcochl62, Jermy 203, Plank 



47; Bexar County, Jermy 22; 



Laredo, Sauvignet in 1892; 



without locality, Nealley in 



1887, Wright 797. 

 New Mexico: Socorro, Plank 38. 

 •Arizona: Tucson, Griffiths 1545, 



1616, 3362, Hitchcock 3495 ; Prin- 



gle in 1881; Papayo E-eserva- 



tion, Griffiths 1654; Santa Rita 



Mountains, Griffiths 7297, 7299. 

 Mexico: Chihuahua, Pringle 379, 380; San Dieguito, Palmer 152 in 1904; Vic- 

 toria, Palmer 412 in 1907; Guaymas, Hitchcock 3561, Palmer 159 in 1887 in 



part. 



Fig. 22.— Distribution of P. fasciculatum chartaginense. 



a See page 44. 

 & Loc. cit. 



c Vet. Akad. Handl. Stockh. 1853: 133. 1855. 

 d Fl. Brit. W. Ind. 546. 1864. 



