SYSTEMATIC BOTANY OF BEANS, AND THEIR ALLIES 



stamens generally monadelphous, the 10th partly (rarely entirely) 

 free; style glabrous; stigma capitate; pods stipitate, oblong or 

 linear, straight or somewhat falcate, ridged near the sutures; seeds 

 globose or ellipsoid, the hilum linear. 



About 40 species are known from the tropics and 

 sub-tropics. About two dozen are native to America. 

 Several species are reported to have poisonous seeds. 

 Only two are important as cultivated plants. These 

 are used for food, forage, green manure, etc. 



KEY TO CULTIVATED SPECIES OF CANAVALIA 

 Pod more than 10 times as long as broad; hilum half as long as 



seed; plant usually bushy 1. C. ertsiformis 



Pod less than 8 times as long as broad; hilum nearly as long as seed; 



plant climbing 2. C. gladiata 



1. Canavalia ensiformis DC. Prod. 2:404. 1825. 

 Jack Bean. — Dolichos ensiformis L. Sp. PI. 725. 

 1753. Dolichos acinaciformis Jacq. Coll. Bot. 1:114. 

 1786. Dolichos pugioniformis Gmel. Syst. Nat. ed. 

 13. 2:1105. 1796. Malocchia ensiformis Savi, Nu- 

 ovo Giorn. Pisa. 10:21. 1825. 



Bushy erect annual, sometimes twining when growing in 

 shade; stems stout, terete, somewhat reflexed, strigillose; petioles 

 usually longer than leaflets; stipules fugaceous; leaflets oval to 

 ovate, 6-12 cm long; flowers rose or light magenta; pods linear 

 slightly curved, beaked at tip, scarcely compressed, 2S-30 cm long, 

 2-2.5 cm wide, 12-20-seeded; seeds ellipsoid, compressed, shiny 

 white, the hilum half as long as seed. Native to Tropical America. 



The jack bean is widespread in the tropics of both 

 hemispheres and is cultivated to a small extent in the 

 southeastern United States, but other species of beans 

 seem more profitable for the various uses to which it 

 is put and it seems likely to be useful only under special 

 conditions. A thorough discussion of this bean is 

 given by C. V. Piper in " The Jack Bean." (U. S. D. A. 

 Circular 92. 1920.) 



2. Canavalia gladiata DC. Prod. 2:404. 1825. 

 Sword Bean. — Dolichos gladiatus Jacq. Coll. Bot. 

 2:276. 1788. Canavalia maxima Thou. Journ. Bot. 

 Desv. 1:78. 1813. Malocchia gladiata Savi, Nuovo 

 Giorn. Pisa 10:24. 1825. 



Annual ipossibly perennial in the tropics) climbing vine; 

 stems green, reflexed strigillose becoming glabrate with age; petioles 

 shorter than leaflets; stipules fugaceous; leaflets broadly ovate; 

 flowers pale pink or pink tinged; pods linear compressed, slightly 

 curved, 20-35 cm long, 3.5-5 cm broad, 8-16-seeded; seeds ellipsoid, 

 more compressed than those of C. ensiformis, the hilum nearly 

 as long as the seed, red or ochraceous, rarely white. Known only 

 from cultivated plants and possibly derived from C. virosa (Roxb.) 

 Wight & Am., a native of India. There are several distinct varieties 

 cultivated in India, Burma, China, Japan, and the southeastern 

 United States. The seeds are said to be very palatable. 



The American species of Canavalia are treated by 

 Piper in the Contributions of the U. S. National 

 Herbarium. 20:555-576, 1925, and the Old World 

 Species were revised by Piper & Dunn in Kew Bulle- 

 tin Misc. Inf. 129-145. 1922. 



3. CAJANUS Adans. Fam. 2:326. 1763. (Here 

 spelled Cajan and properly latinized by De Candolle 



in Horr. Bot. Monsp. 85. 1813.) — Cajanum Raf. 

 Sylva Tellur. 25. 1838. 



Erect shrubs with stout tap root and numerous lateral nodule- 

 bearing, rootlets; branches angular, furrowed; leaflets 3, entire 

 lanceolate; petioles shorter than the leaflets; stipules deltoid subu- 

 late, fugaceous; flowers in axillary racemes toward the tips of the 

 branches; calyx with 2 upper lobes united; standard broad, auricled; 

 keel blunt; stamens diadelphous (9 and 1); pod flattish, somewhat 

 constricted between the seeds; seeds usually 3, 4, or 5. 



Perhaps two or three species of which the only one 

 well known is the following: 



Cajanus cajan Millsp. Field Columb. Mus. Bot. 

 2:53. 1900. Pigeon Pea.— Cytisus cajan L. Sp. PI. 

 739. 1753. Cajan inodorum Medic. Vorl. Ch. 

 Phys. Geo. 2:363. 1787. Cajanus flavus DC. Car. 

 Hort. Bot. Monsp. 86. 1813. Cajanus indicus 

 Spreng. Syst. 3:248. 1826. Cajanum thora Raf. 

 Sylva Tellur. 25. 1838. Cajan cajan Huth, Helios 

 11:133. 1893. 



Erect bushy shrub; branches finely pubescent; leaflets acute, 

 3-10 cm long, 2.5-3.5 cm wide, grayish tomentose underneath; 

 stipules deltoid subulate; calyx pubescent, the lobes acute; standard 

 orbicular, indexed at the basal auricles; wings obliquely obovate; 

 style slender thickened in the middle; stigma capitate, oblique; 

 pod 5-8 cm. long, linear, straight or curved, beaked. Probably 

 native to tropical Africa but cultivated and run wild throughout 

 the tropics and subtropics. 



Sturtevant (Notes on Edible Plants 124. 1919) 

 says " It is certainly one of the oldest cultivated plants 

 in the world . . . Schweinfurth states that it is 

 found in Egyptian tombs of the twelfth dynasty (2200- 

 2400 B.C.)." 



The typical form apparently is a pure yellow flowered plant 

 with rather small red seeds. Krauss | The Pigeon Pea. Hawaii 

 Agr. Exp. Sta. Bull. No. 46. 6. 1921.) says that " it is early 

 maturing and very heavy seeding, yielding a heavy crop of seeds 

 within 7 or 8 months from time of planting but attaining in the 

 second year a height of only 3 to 7 feet." The following seems to 

 be a well marked form. 



C. cajan forma 1 bicolor Van Es. comb. nov. — C. bicolor DC 

 Cat. Hort. Bot. Monsp. 85. 1813. C. striatus Boj. Hort. 

 Maurit. 109. 1837. C. lutens Bello. Anal. Soc. Esp. Hist. 

 Nat. 10:260. 1881. 



This form has yellow flowers tinged with red, and light grey, 

 faintly speckled seeds somewhat larger than those of the species. 

 Krauss (I.e.) states that it "does not begin to yield its maximum 

 crop until the second year, — and attains a height of from 6 to 

 10 feet." 



There are apparently several strains of each form in 

 cultivation. The seeds are eaten like peas and are said 

 to be equally palatable; the leaves furnish excellent 

 forage; and the plants are very valuable for enriching 

 the soil. 



4. DOLICHOS L. Sp. PI. 725. 1753.— La blab 

 Adans. Fam. 2:325. 1763 (Latinized as Lablavia D. 

 Don, in Sweet, Brit. Fl. Gard. II. 3:236. 1834). 

 Dipogon Leibm. Ann. Sci. Nat. IV. 2:374. 1854. 



Twining, trailing or suberect herbs and subshrubs; leaves 

 3-foliolate, stipellate, the stipules small; flowers axillary, solitary 

 or in close racemes, white, yellow, reddish, or purple; calyx lobes 



1 In the treatment of subdivisions of species in this work the terms subspecies and forma are used entirely throughout the botanical 

 section. The term variety is here used only in the horticultural sense except in the citation of synonyms where such a course is 

 impossible. It is felt that much confusion will be thus avoided. 



