238 CONTRIBUTIONS PROM THE NATIONAL, HERBARIUM. 



4. MERTENSIA Roth. 



1. Mertensia virginica (L.) DC. Bluebells. 



Alluvial soil along the Potomac; common. Apr .-May. Eastern N. Amer. 

 One of the showiest spring flowers. Plants with white flowers are sometimes found. 

 Known also as Virginia cowslip and lungwort. 



Asperugo procumbens L., native of Europe, was collected in waste ground about 

 Washington in 1898. 



5. MYOSOTIS L. Forget-me-not. 



Myosotis scorpioides L., the common forget-me-not, with blue flowers, was collected 

 In Washington, June, 1897 (Kearney). Native of Eur. and Aeia; often cultivated and 

 frequently escaping in the eastern IT. S. 



Hairs of the calyx all straight; plants perennial; flowers blue 1. M. laxa 



Hairs of the calyx, at least some of them, with hooked tips; plants annual or biennial; 

 flowers white. 

 Calyx not over 5 mm. long at maturity; fruiting racemes with many close flowers, 



these on erect or ascending pedicels; nutlets 1.5 mm. long 2. M. virginica. 



Calyx 6-7 mm. long at maturity; fruiting racemes with few remote flowers, these on 

 usually recurved pedicels; nutlets 2 mm. long 3. M. macrosperma. 



1. Myosotis laxa Lehm. 



Wet soil, usually along streams or ditches; frequent. May-Aug. Eastern X. Amer. ; 

 also in Eur. (M. palustris of Ward's Flora.) 



Myosotis arvensis (L.) Hill, a blue-flowered species, was collected in the Department 

 of Agriculture grounds, May, 1905 (House). Eastern N. Amer., perhaps adventive; 

 also in Eur. 



2. Myosotis virginica (L.) B. S. P. Scorpion-grass. 

 Dry or wet fields and hillsides; frequent. May. Eastern U. S. ( M. verna Nutt.) 



3. Myosotis macrosperma Engelm. 



Wet soil; Congress Heights and along the lower Potomac. May-June. South- 

 eastern U. S. (M. arvensis of Ward's Flora; M. virginica macrosperma Fernald.) 



6. LITHOSPERMUM L. 



Flowers white, about 6 mm. long, mostly in the leaf axils, the corolla tube about as 

 long as the calyx lobes; plants annual or biennial 1. L. arvense. 



Flowers bright yellow, about 12 mm. long, in short leafy racemes, the corolla tube 

 much longer than the calyx lobes; plants perennial 2. L. canescens. 



1. Lithospermum arvense L. Corn gromwell. 

 Dry fields and roadsides; common. Apr. -May. Native of Eur.; widely natu- 

 ralized in N. Amer. 



The roots of this and the following Bpecies contain a purple dye. 



2. Lithospermum canescens (Michx.) Lehm. Hoary puccoon. 

 Woodley Road and near Langley, in 1877 and 1884 (Ward). Eastern N. Amer. 



7. ONOSMODIUM Michx. 



1. Onosmodium virginianum (L.) DC. False gromwell. 



Dry hillsides; Terra Cotta, Bladensburg, Difficult Run, and Great Falls. June 

 Eastern U. S. 



Symphytum officinale L., comfrey, was collected at Woodside, June, 1896 (//. W. 

 Oldys). Native of Eur. and Asia; sometimes adventive in eastern N. Amer. 



Borago officinalis L., borage, was collected at Foundry Run, June, 1885 (A. L. 

 Schott). Native of Eur.; occasionally adventive in eastern N. Amer. 



