154 Rhodora [SEPTEMBER 
ermanni and P. Gattingeri have a much denser pubescence, more 
pointed spikelets, and pubescent nodes. The form under discussion 
has glabrous nodes. From P. capillare it can be distinguished by the 
glabrous pulvini.! 
So far as is known this plant occurs 
only on the sandy pond-shores of south- 
eastern Massachusetts. It is distin- 
guished from the typical P. dichotomi- 
florum by low habit, and scattered in- 
florescence of small, blunt spikelets with 
long pedicels. Most characteristic are 
the second glume and sterile lemma 
which are somewhat membranaceous, 
and have a tendency to spread and 
wither at maturity, exposing the fruit. 
This plant is worthy of varietal separa- 
tion as: 
PANICUM DICHOTOMIFLORUM Michx., 
var. puritanorum, n. var. annuum, 
culmis plerumque erectis rare decum- 
bentibus vel solitariis vel numerosis fur- 
catisque, 0.5-6 dm. longis ubique foliosis; 
vaginibus glabris vel pilosis, laminis 2-40 
cm. longis, 0.1-8 mm. latis longe acumi- 
natis laxe adscendentibus glabris vel his- 
pidis; paniculis numerosis vel solitariis, 
primariis breviter exsertis, late ovoideis, 
3-25 em. longis; ramis primum adscen- 
dentibus deinde divergentibus vel rare 
reflexis, pulvinis glabris; spiculis ovoideis, 
longe pedicellatis, 1.8-2.2 mm. longis, 
0.8-1.1 mm. latis obtusis vel acutiusculis, 
gluma prima deltoideo-orbiculare spiculo 
quater vel quinquiens breviore; gluma 
Fig. 1. P. dichot. v. puritanorum altera et lemmate sterili 5-7-nervatis, 
D submembranaceis caryopsin vix superan- 
tibus plerumque flaccidis vel ad maturitatem marcescentibus et cary- 
opsin denudantibus. 
Culms usually erect, solitary or numerous, simple or branching from 
base and nodes, 0.5-6 dm. long, leafy throughout: sheaths glabrous 
or pilose, blades 2-40 em. long, 0.1-8 mm. broad, long-acuminate, 
l For elucidation of this character see Ruopora, l. c. ITI. 
