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ELEMENTARY NOTES ON JAMAICA PLANTS. 



1. LlMXANTHEMUM HuMBOLDTIANUM, GRISEB. 



Humbolcb's Pond Flower. 

 This beautiful little aquatic, at the first glimpse we get of it in ponds, 

 looks like a minature Water Lily with its white flowers and floating 

 leaves. 



An examination however of the structure of the flower will show how 

 very different it is from the true Water Lilies, — Nymphaea and 

 Nelumbium. 



A Xymphaea has numerous petals all separate from one another, 

 whereas this plant, as may be seen in figures b & e, has its petals united 

 to one another. 



We may give it an English name, and call it " Pond Flower," which 

 is the meaning of Linnanthemum, or " Humboldt's Pond Flower" 

 which connects its geographical extension from Mexico to South 

 Brazil and the West Indies with the name of the great traveller through 

 these lands. 



It is beautifully adapted to its aquatic life. The leaf shoot springs 

 from under water, at first with the edges of the leaf rolled up tight, 

 so that there is no resistance as it gradually rises out of the water. 

 Then the leaf unrolls, and sinks on the surface a floating leaf, support- 

 ing the plant, and providing for the opening of the flower above the 

 water where moths or other insects can visit and fertilise it. 



The flowers spring several together from a point on the shoot just 

 below the blade of the leaf. If the drawings b & e are compared, it will 

 be seen that some flowers have a long pistil and short stamens, whilst 

 othei shave a short pistil and long stamens. This arragement is for the 

 purpose of ensuring cross-fertilisation, which is so much more ad- 

 vantageous to the species than self-fertilisation in securing better seeds. 

 A moth visiting the flower for the purpose of sucking the honey 

 sicreted by a small gland at the base of the petal (fig. e), puts its long 

 tongue between the pistil andthe petal. If the flower has a short pistil, 

 the stamens are high up above it, and the insect's tongue touching them is 

 dusted with pollen When it goes to a flower with short stamens, the 

 place on its tongue covered with pollen reaches the stigma of the pistil, 

 and fertilises the flower with pollen from the other flower, at the same 

 time carrying off pollen for a flower with long stamens. 



When the flower is fertilised, it gradually bends over, as shown in 

 the figure, sinks below the surface of the water, and ripens its seed there 

 in seclusion to drop into the mud below. 



There are certain features in the structure of the flowers which show 

 a f amilv resemblance to other plants, and all these plants are accordingly 

 classed together as a natural family, or order, called Gentianeae from the 

 gentians which "are so abundant on the Alps of Switzerland. These 

 family features should be carer ully observed in all the plants of the 

 order that can be found, and the differences amongst the family groups, 

 or genera, also noted. 



Ihe commonest plants belonging to this order in Jamaica are species 

 of Leiaxthus, which have flowers looking very much like yellow 

 Fuchsias. One species Leianthus vmbeilatics, forms a small handsome 

 tree, a most unusual form, as the Gentian order is almost universally 



