BALSAMINE^. 6l 



do so when ripe so violently that the seeds are ejected 

 some considerable distance. It is to this explosiveness 

 of the capsule that the genus IMPATIENS owes its name. 



The flower is therefore on the 5, 5, 5, 5, plan, except 

 that two of the sepals are usually absent ; and its pecu- 

 liar appearance is due to the differences of size of the 

 sepals and petals, and the fusion of the lateral pairs of 

 petals to form the wings. A spurred sepal occurs also in 

 TROPiEOLUM, the common garden Nasturtium ; and also 

 in PELARGONIUM, the garden Geranium, where however 

 it is fused to the flower-stalk and so invisible. Both 

 these genera are included in the family GERANIACEiE of 

 the Gen. Plant. The stem is usually smooth, more or less 

 translucent, and conspicuously swollen at the nodes ; 

 and the leaves are always crenate or serrate, with 

 rounded teeth ending in sharp points which at the base 

 of the leaf, where there are hardly crenations, appear as 

 glandlike hairs perhaps 1/16 inch long. 



The genus impatiens, the true Balsams, is one of the largest among 

 flowering plants, there being over 400 species described, and is found chiefly 

 on the mountains of tropical Africa and south-east Asia (India, China, 

 and Malaya). North America has two species only, Europe one, Siberia 

 two, Japan four, — these are all closely allied ; while in tropical Africa there 

 are nearly fifty species, in India about two hundred and in China about as 

 many. But there are none at all in Australia, New Zealand, Polynesia, or 

 the whole continent of South America, so that this is essentially a genus of 

 the Old World tropics, with Borneo and the Phillipines as the eastern limit. 

 In India itself, the distribution is remarkably local. There are six well- 

 defined regions, shown on the accompanying map of this country, and of 

 the two main series into which the species naturally fall (130 with short 

 swollen spindle-shaped pods, and 60 with long and narrow or club-shaped 

 ones) one only of the first occurs in the north-western Himalayas, and of 

 the second not one in South India, Ceylon or the Malay Peninsula. The 

 Western Ghats are peculiarly rich in species, especially Travancore, and 

 out of the 54 species described from the Nilgiris and the mountains to the 

 south, 24 are peculiar to the Pulneys and Travancore. Most of these grow 

 however at lower elevations than ours. 



The narrowness of the distribution of each series, and of most of the 

 species, seems to point to their having arisen in their separate areas after the 

 conditions, whether of climate or some other factor which had allowed of 

 free intercourse between the areas had passed away and left parts of the 

 genus marooned, so to speak, on the higher hills : for the hot plains between 

 are barriers for such a delicate plant, as impossible of crossing as are 

 the seas to most animals. A similar confinement of species to small 

 areas was found by Charles Darwin in the flora of the Galapagos islands, 



