THE TAWNY BALSAM— continued. 
unequal development and cohesions make it difficult to decide which parts belong 
to the calyx and which to the corolla. Although at first sight there appear to be 
only six leaves to the perianth, of which three are sepals and three petals, there are 
normally ten leaves, five sepals, and five petals. The two outer sepals are lateral 
and opposite one another : the two anterior are often suppressed ; and the upper or 
posterior one, though by the twisting of the flower-stalk it hangs lowest, is the wide 
pouch or spur. The inner lateral petalline leaves, which are more or less unequally 
bilobed, represent two pairs of petals — postero-lateral and antero-lateral — each leaf 
being formed of a petal from each pair, the broad, concave, symmetrical, odd petal 
being in reality anterior. The five stamens have short, broad, coherent filaments, 
and introrse anthers united in a cap over the ovary, which are mature when the 
flower first opens, when the enclosed gynaeceum is still rudimentary. 
There are five united, multi-ovulate carpels, the partition- walls between which 
are thin and soon disappear, leaving a persistent central axis to which the seeds are 
attached. The growth of the young ovary breaks the stamens away at their bases, 
the pollination of the flowers being effected in England by humble-bees visiting 
flowers in two different stages of development. In its native country — the eastern 
United States — I. biflora Walter, often known as I.fulva Nuttall, the name which we 
have literally translated, is pollinated, occasionally at least, by humming-birds. 
The pericarp remains fleshy and sometimes green ; but, as the seeds ripen within it, 
unequal tensions are set up in it between oblique, partly lignified cells and the outer 
epidermis, with the result that, if touched, or warmed by bright sunshine, the five 
valves coil up inwards from below upwards, discharging the seeds with great force. 
It is to this action that the Balsams owe their generic name Impatiens, first used 
apparently by Dodoens. 
It was in 1822 that John Stuart Mill first noticed the American Impatiens biflora, 
with its orange flowers spotted with red and sharply upturned spur, by the banks of 
the Tillingbourne, in Surrey, it being probably an escape from the gardens at 
Albury. Since then it has spread to the Wey, from the Wey to the Thames, and 
from the Thames up the Colne into Hertfordshire, and along streams, canals, and 
ditches in all directions, and often in great profusion. A smaller, paler-flowered 
Siberian species, U. parviflora De Candolle, is almost as well established. 
