492 Cruciferae Raphanus 



Upper stem leaves not clasping. 



Beak of pod terete, much narrower than the pod, a ninth to a fourth of the total 

 length of the fruit, without a seed near the base. 

 Pods 3-6 cm long, 2-3.5 mm thick, somewhat 4-sided, spreading; beak 6-12 mm 



long; pedicels 7-10 mm long, equaling or exceeding the flowers 



2. B. juncea. 



Pods 1-2 cm long, about 1 mm thick, appressed; beak 1.5-2.5 mm long; valves 



with 1 conspicuous nerve; pedicels 3-6 mm long, shorter than the flowers 



3. B. nigra. 



Beak of pod flat, about as wide as the body, a fourth the length of the fruit, usually 



containing a seed at the base. 



Fruiting pedicels mostly 3-7 mm long; pods moderately slender, about 2 mm in 



diameter, glabrous or hispid, ascending, valves distinctly 3-nerved, the beak 



usually a fifth to a third the length of the fruit; lower leaves sparingly 



lyrate, the upper ones usually undivided 4. B. kaber var. pinnatifida. 



Fruiting pedicels about 10 mm long; pods stout, about 4 mm thick, hispid, spread- 

 ing at right angles, valves indistinctly nerved, beak very broad and flat, 

 usually more than half the length of the fruit; leaves more lyrate. (See 

 excluded species no. 259, p. 1051.) B. hirta. 



1. Brassica campestris L. Field Mustard. Map 1008. This weed 

 has been reported twice for the state and I have specimens from two 

 counties. Almost all crucifers are of a weedy nature. Peattie says it is 

 established in the Calumet Region and I found it to be plentiful in the 

 old Fair Grounds at Lawrenceburg, Dearborn County. 



Nat. of Eu. and widely distributed in N. A. 



2. Brassica juncea (L.) Cosson. Indian Mustard. Map 1009. 

 There are two reports of this weed and I have specimens from three coun- 

 ties. I have always very much disliked the introduced species of crucifers 

 and have neglected to collect them. If I had appreciated the necessity of 

 collecting these weeds, no doubt my records would be more numerous. 



Nat. of Asia, but of recent introduction. 



3. Brassica nigra (L.) Koch. Black Mustard. Map 1010. This is 

 a frequent to common weed throughout the state. It prefers a sandy 

 soil as crucifers usually do. 



Nat. of Eurasia; generally distributed throughout the U. S. 



4. Brassica kaber (DC.) Wheeler var. pinnatifida (Stokes) 

 Wheeler. (Rhodora 40: 306-308. 1938.) (Brassica arvensis (L.) Raben- 

 horst. of Gray, Man., ed. 7 and Sinapis arvensis L. of Britton and Brown, 

 Illus. Flora, ed. 2.) Charlock. Map 1011. This weed has been reported 

 from 13 counties. It is found not only in waste places and along lines 

 of transportation but also in cultivated and fallow fields. 



Nat. of Eu. and widely distributed in N. A. 



2950. RAPHANUS [Tourn.] L. 



Flowers pale yellow (fading white in herbarium specimens) ; pods 3.5-4 mm in 

 diameter, longitudinally grooved, 4-10-seeded, the seed-bearing part longer and 

 more slender than that of the following species 1. R. Raphanistrum. 



Flowers white or purplish; pods 2- or 3-seeded, the seed-bearing part short and thick, 



at maturity sometimes 10 mm in diameter, not grooved. (See excluded species 



no. 262, p. 1052.) R. sativus. 



