16 



THE VEGETABLES OF NEW YORK 



P. lunatus var. macrocarpus Benth. in Mart. Fl. 

 Bras. 15:181. 1862. P. amazonicus Benth. 1. c. 



Climbing or erect, pubescent or glabrate; leaves 3-foliolate, 

 leaflets ovate or rhomboid, acute, entire, 5 to 14 cm long, dull 

 green above, paler beneath; stipules small, deltoid; flowers numerous, 

 small, greenish yellow or white, in racemes at the end of peduncles 

 as long or longer than the petioles; calyx bracts linear to oval; calyx 

 broadly campanulate with broad deltoid lobes; pods 5 to 12 cm 

 long, 2 to 2.5 cm wide, the margin variously thin to very thick, the 

 beak sharp and slender to stout and blunt; seeds flat and thinnish, 

 or thick oval, 1.0 to 2.0 cm long with more or less conspicuous lines 

 radiating from the hilum. Native to tropical America, but widely 

 grown throughout the world and firmly established in many places. 



There are three outstanding groups in cultivation in 

 America, viz., the so-called Big Limas, the Potato 

 Limas, and the Sieva or Small Lima beans. All varia- 

 tions between these types seem to exist in wild plants 

 from Central and South America and indeed, many of 

 these varieties have found their way into Africa and the 

 far East. Under such conditions it seems inadvisable 

 to treat the cultivated segregates as distinct botanical 

 subspecies, though it may be well to include them as 

 forms in order to have ready reference to the variations 

 listed in various publications. For a more detailed dis- 

 cussion of these forms, the reader is referred to "Varia- 

 tion in the Lima Bean, Phaseolus lunatus, as 

 illustrated by its synonymy." New York State 

 Agr. Exp. Station Technical Bulletin 182. 1931. 



The following forms have been distinguished: 

 (a) forma macrocarpus Van Es. 



This is the big lima type often listed as var. macrocarpus 

 Benth. or as P. limensis Macf 



(b) forma salicis Van Es. 



This form is the willow leaved type described as Phaseolus 

 lunatus var. salicis Bailey Gent. Herb. 1:123. 1923. 



(c) forma lunonanus Van Es. 



The dwarf bush Sieva type was described as Phaseolus 

 lunatus var. lunonanus by Bailey /. c. 



(d) forma limenanus Van Es. 



The bush or dwarf form of the big lima was described as 

 Phaseolus limensis var. limenanus by Bailey 1. c. 125. 



(e) forma solanoides Van Es. 



The so-called potato type differs from other forms in the more 

 triangular leaflets and the more nearly spheroidal seeds. 



Since neither flower characters nor those of the 

 fruit and leaf can be used to separate the material grown 

 outside the United States, it is thought best for the 

 purpose of this volume to hold all forms under the 

 specific name Phaseolus lunatus and to leave the 

 subdivisions of the group to the ordinary horticultural 

 practice as given in the succeeding chapters. In this 

 connection the opinion of that careful student of the 

 legumes, C. V. Piper, should be quoted. After years 

 of work with the entire group, he says, " This is a very 

 diverse aggregation of both wild and cultivated forms 

 whose status is variously interpreted by different 

 botanists. In the writer's judgment it is but a single 

 botanical species." (Studies in American Phaseo- 

 lineae, Contr. U. S. N. H. 22:694. 1926.) 



The American horticultural varieties are all of 

 comparatively recent development and the selection 

 work of Shaw {California Agr. Exp. Sta. Bulletin 

 238. 1913.) seems to show that a fruitful field in 

 breeding awaits the experimenter in this group. 



Two diseases, downy mildew (Phytophthora 

 phaseoli) and pod blight (Diaporthe phaseolorum) 

 are reported as specific to this crop. Bacterial spot 

 (Bacterium vignae) also is reported to attack both 

 pods and leaves. 



