EXPLANATION OF THE ILLUSTRATION 
Karyotypes of Chihuahuan umbelliferae 
a, Donnellsmithia ternata (S.Wats.) Math. & Const., Diak., Bye 4393: 
b, D. silvicola Const. & Bye, Diak., Bye 6376; ¢e, Tauschia bicolor 
Const. & Bye, Diak., Bye 3863; d, 7. tarahumara Const. & Bye, MII, 
Bye 6288; e, drracacia edulis S,Wats., Diak., Bye 6753; f, Eryngium 
Jluitans M.E.. Jones, MI, Bye 4763; g, FE. Gentryi Const. & Bye, 
Diak., Bye 4766; h, FE. heterophyllum Engelm., Diak., Bye 4334; i, 
Ek. Lemmonii Coult. & Rose (EF. calaster Standl.), MI, Bye 4463; j, 
EF. Lemmonii Coult. & Rose (FE. calaster Standl.), MII, Bye 4809; k, 
KE, phyteumae Delar.t., MIL, Bye 5905 (Const. 1906). (Diak.—= Dia- 
kinesis; MI, MII-Metaphases I and II. All ea. 1050). 
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