148 LEGUMINOSAE 



inward and obtuse. The stamens are arranged in 2 groups, 

 and the ovary develops into an elongated, leathery pod contain- 

 ing several seeds. 



There are seven species of wisteria native in Asia and two 

 native in North America. Only the following occurs in Illinois 

 as a woody vine. 



WISTERIA MACROSTACHYA Nuttall 



Wisteria 



The Wisteria, fig. 34, is a slender, climbing vine with long 

 stems, sometimes 20 to 25 feet in length, bearing sparingly pu- 

 bescent young branches, which soon become glabrous, and alter- 

 nate, pinnately compound leaves composed usually of 9 leaflets 

 set alternately but more or less definitely in pairs along the 

 rachis. The leaflets are ovate to elliptic, 1 to 2^ inches long, 

 acuminate at the tip, and rounded to almost cordate at the 

 base. The margins are smooth and the surface, although pu- 

 bescent at first, becomes glabrous with maturity or remains 

 only sparingly pubescent. 



The lilac to purple, showy flowers are borne in dense racemes 

 8 to 12 inches long, which, although terminal, are loosely flow- 

 ered and drooping. Both rachis and lower pedicel are hairy 

 and glandular with cup-shaped glands. The bell-shaped, pu- 

 bescent calyx has lower teeth at least half as long as the 

 tube. The standard of the corolla is not prominently eared, 

 but the wings bear an awl-shaped spur at the base about as 

 long as the claw. The flowers are in blossom from July to 

 August, and the fruit, which ripens in fall, is an elongated pod 

 2 to 4 inches long, which is narrowed between the seeds and 

 contains several black, shining seeds. 



Distribution. — This wisteria is an inhabitant of swampy 

 woods and ranges from southern Illinois to Louisiana and 

 Texas. In Illinois, it is limited to a very small portion of the 

 southern part of the state, not extending north beyond the 

 Ozarks at any point. It has thus far been recorded in Pope, 

 Pulaski and Alexander counties only, in one instance as a 

 fence climber, but elsewhere only as a climbing vine in the rich 

 bottomland forests along the southern rivers. Early reports of 

 Wisteria frutescens (Linnaeus) Poiret in Washington and other 

 southern counties are undoubtedly referable to this species. 



