70 
NAT. ORDER. ONAGRARI^. 
and a little more than a half an inch in breadth ; the flowers are 
solitary, each being separated by a leaflet or bracte, wider in propor- 
tion at the base than the proper leaves, and drawn more to a point 
diminishing gradually towards the top of the spike, till they become 
linear, scarcely half an inch in length, and a line in breadth. 
It is observed that the flowers usually open between six and seven 
o'clock in the evening, whence the plant is called Evening or Night- 
Primrose ; the flowers nearest the top of the stem bloom first in 
June, the stalk keeping constantly advancing in height, and there is 
a constant succession of flowers till late in the autumn. It is a 
native of North America. The roots are frequently eaten by the 
natives in the spring season. 
Oenothera longiflora. Long-flowered Tree-Primrose. This species 
has also a biennial root ; the root-leaves are numerous, broad-lance- 
olate, tooth-letted, pubscent, with a white rib, obliquely nerved ; the 
stems usually five, springing out below the root-leaves, quite simple, 
ascending, rough-haired, green, with long spreading hairs ; the cen- 
tral stem grows up later ; the stem-leaves are ovate-oblong, sessile 
like the root-leaves ; the flowers axillary from the upper leaves, with 
the germ and calyx hairy. It is remarked by Curtis, that luxuriant 
specimens exceed five feet in height, that the flowers are uncommonly 
large and showy, and continue blooming from July to October. It 
is a native of Buenos Ayres. 
Oenothera moUissima. Soft Tree-Primrose. This species has a 
shrubby stalk more than two feet high, hairy, with narrow, lanceo- 
late leaves, a little waved on their edges, and ending in acute points ; 
the flowers are axillary, like the other sorts, at first pale yellow, but 
as they decay changing to an orange color, smaller than those of the 
first sort; the seed-vessels are slender, tapering and hairy. It is also 
a biennial plant, and a native of Buenos Ayres. It flowers from 
June to October. 
Oenothera biennis. Broad-leaved Tree-Primrose. This species 
is a perennial, but altogether herbaceous, at least in this country, 
