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Linnaeus attributed to the Impatiens Balsamina a calyx of 2 leaves, 5 un- 
equal petals, a nectaiy, a single ovary, a sessile stigma, and a unilocular poly- 
spermous capsule, opening in 5 valves. M. de Jussieu describes it nearly in 
the same way, with the exception of considering the capsule as having 5 cells, 
and the corolla as consisting of 4 petals, the lower of which is spurred. These 
erroneous characters have been reproduced by most authors. Dr. Hooker alone 
refers the part which has the spur to the calyx, which he consequently makes 
to consist of 3 pieces. M. Achille Richard has come nearest the truth in the 
Dictionnaire Classique, where he describes the calyx as consisting of 4 pieces, 
and the 4 petals united in pairs. The fact is, that the structure is usually this : 
the centre of the flower is occupied by an ovariuni, surmounted by a stigma 
divided into 5 acute lobes. Around this stand 5 hypogynous stamens, placed 
in a single row and at equal distances from each other. Hence the normal 
number of the parts of the flower should be 5 . The corolla, however, consists 
of 2 bifid petals placed right and left, with a wider space between their upper 
than their lower edges. Upon comparing the position of these with the 
stamens, it appears that each occupies the place of 3 stamens, whence it is 
impossible to doubt that they each consist of 2 soldered together. On the 
other hand, the space between them, which answers to 2 stamens, is an equal 
proof of the abortion of a fifth petal. And this view of the structure is con- 
firmed by the sepals. Thus on the outside of each pair of petals, at their base, 
is found a leaflet, the situation of which is opposite a stamen ; and opposite the 
space left by the abortion of the fifth petal is a large broad leaflet, made up by 
the union of 2 sepals. The position of the fifth sepal, which is that which is 
spurred, is between 2 petals and opposite a stamen. 
Geography. Natives of damp places among bushes in the East Indies ; 
1 is found in Madagascar, 1 in Europe, 2 in North America, and 1 in Russia 
in Asia. 
Properties. Chiefly remarkable for the elastic force with which the 
valves of the fruit separate at maturity, expelling the seeds. For a supposed 
explanation of this phenomenon, see Dutrochet, Nouvelles Recherches sur 
V Exosmose et Endosmose. According to De Candolle, the species are diuretic. 
GENERA. 
Balsamina, Riv. Hydrocera, Bl. 
Impatiens, L. Tytonia, G. Don. 
Sub-Order. TROP^OLE^. The Nasturtium Tribe. 
Trop^ole^, Juss. Mem. Mus. 3. 447. (1817) ; DC. Prodr. 1. 683. (1824). 
Essential Character. — Sepals 5, the upper one with a long distinct spur; (Estivation 
quincuncial. Petals 5, unequal, irregular, the 2 upper sessile and remote, arising from the 
throat of the calyx, the 3 lower stalked and smaller, sometimes abortive. Stamens 8, peri- 
gynous distinct; anthers innate, erect, 2-celled. Ovary 1, 3-cornered, made up of 3 car- 
pels ; style 1 ; stigmas 3, acute ; ovules solitary, pendulous. Fruit indehiscent, separable 
into 3 pieces from a common axis. Seeds large, without albumen, filling the cavity in 
which they lie ; embryo large ; cotyledons 2, straight, thick, consolidated together into a 
single body ; radicle lying within projections of the cotyledons. — Smooth herbaceous plants, 
of tender texture and with an acrid taste, trailing or twining. Leaves alternate, without 
stipules, petiolate, with radiating ribs. Peduncles axillary, 1-fiowered. 
Anomalies. Magallana has winged fruit, 1 -celled and 1 -seeded by abortion. In Chy- 
mocarpus the calyx is valvular, and the petals only 2. 
Affinities. Very near Geraniaceae, with which they agree even in their 
spur (which in Pelargonium is often present, but adnate to the pedicel). From 
