30 DESMANTHUS BRACHYLOBUS. ILLINOIS ACACIA. 



even drops its leaflets, when cut. In the specimen taken by our 

 artist some of them had fallen before he had finished his task, 

 as may be seen in his faithful reproduction. It is more interest- 

 ing when in fruit than in flower, as the curved mass of greenish- 

 brown immature pods make a pretty contrast with the lighter 

 lines of its numerous small leaflets. If the main stems only had 

 a little more lightness, and were somewhat curving as they 

 often are in ferns, there would be few plants able to cope with 

 it in this particular style of beauty. 



Both the genus and the species have an interesting botanical 

 history. Some of the species have been long known, but they were 

 classed with Acacias and Mimosas ; plants with which most intelli- 

 gent readers are more or less familiar. Michaux knew them as 

 Mimosa, and in his Flora of North America, published in 1803, our 

 present species is described as Mwiosa Illiiwcnsis. Willdenow was 

 the first to detect the essential difference from Mimosa, and in 1805 

 established the genus DcsmantJms as it now stands. The chief 

 difference is in the seed-pods. In DcsviautJms they are flat, mem- 

 braneous, with several seeds (Fig. 3), and split open at the edges 

 as a pea or a bean would do ; while Mimosa does not split open, 

 but breaks off transversely into as many pieces as there are seeds 

 in the pod. Succeeding botanists attempted to divide the genus 

 still further, and Decandolle made a new genus of our present 

 species, naming it Darlingtoiiia in honor of Dr. Darlington, of 

 Pennsylvania, one of the most intelligent and esteemed botanists 

 of the past age. The chief difterence relied on to distinguish 

 Darlingtonia from Dcsvianthus was in the sexual character of 

 the flowers. In DesmantJms the flowers are not all with stamens 

 or pistil in the same flower, but as botanists would say the flowers 

 were polygamous ; while in the proposed Darlingtonia they are 

 always perfect, that is to say with all the parts necessary to com- 

 pleteness in each flower. But in these days characters of this kind 

 have little value in determining genera, and the more modern 

 name of Darlingtonia has been abandoned for the plant's earlier 

 name of Dcsmantlms. It is interesting to note that when Dr. 



