240 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Autumnal form spreading, with geniculate nodes and elongated, arched internodes, 
rather sparingly branching from the middle nodes, the primary branches elongated, 
the ultimate branchlets shorter than the internodes. 
DISTRIBUTION, 
Known only from Castle Crag, Shasta County, California, where it is found in 
meadows, 
CaLiFORNIA: Castle Crag, Greata in 1899, Hitchcock 3072. 
Columbiana.—Culms stiff, pubescent with appressed or ascending villous hairs, or 
crisp-puberulent, the sheaths pubescent like the culms or nearly glabrous; 
ligules usually less than 1 mm. long, rarely 1.5 mm. long; blades firm, thick, 
stiffly ascending, not over 7 mm. wide; spikelets pubescent, 1.3 to 3.2 mm. 
long, 5 to 9-nerved. Autumnal form freely branching, the branches and stiff 
blades mostlyappressed. With 
the exception of P. tsugetorum, 
confined to dunes and dry 
sands of the Coastal Plain, 
Massachusetts to Florida. 
The species of this group 
form a lineal series from P. 
malacon with spikelets 3.2 
mm. long to P. columbianum 
thinium with spikelets only 1.3 
mm. long. With the excep- 
tion of P. malacon and P. wil- 
mingtonense, there are con- 
necting forms between the successive species in this series, especially between 
P. commonsianum and P. addisonii, and between P. tsugetorum and P. colum- 
bianum. These intermediate specimens are, however, comparatively rare. 
On the other hand, P. oricola and hairy forms of P. tsugetorum make a 
clear cut division between the Lanuginosa and Columbiana impossible. 
Fia. 256.— Distribution of P. shastense. 
Spikelets 2 to 3.2 mm. long, mostly elliptic. 
Winter blades elongated, 5 to 10 cm. n tongs *pikelets 2 
mm. long; plants blue green....................-145. P. wilmingtonense. 
Winter blades 1 to 3 cm. long. 
Spikelets 3.2 mm. long; first glume conspicuously 
distant....-.-...-.--222--222---0---------- 142. P. malacon, 
Spikelets not over 2.5 mm. long; first glume not 
distant. 
Spikeletsabout 2.4 mm. (2.2 to 2.4 mm.) long; 
panicle open, branches stiffly spreading ..143. P. commonsianum. 
Spikelets 2 to 2.1 mm. long; panicle rather dense, 
branches ascending.......-.-.----------- 144. I 
Spikelets not over 1.9 mm. long, obovate, turgid. 
Culms crisp-puberulent or appressed-pubescent with 
crimped hairs; plants bluish or grayish green; pan- 
icles about 3 to 7 cm. long. 
Spikelets 1.8 to 1.9 mm, long...................-.- 146. P. tsugetorum. 
Spikelets 1.5 to 1.6 mm. long................-...-- 147. P. columbianum. 
Culms appressed or ascending-pilose; spikelets not over 
1.5 mm, long, rounded and turgid; plants oliva- 
ceous; panicles rarely more than 3 cm. long. 
Spikelets 1.5mm. long; culms rather stout; autumnal 
form branching from all the nodes........... 148. P. oricola. 
=| 
. addisoni. 
~ 
