$modus 0:
$modus 1:
Crataegus viburnifolia
Crataegus viburnifolia Sarg. [Accepted]
Rosaceae Rosoideae Crataegeae
2 285469 Crataegus viburnifolia Sarg.
C.S. Sargent, Trees & Shrubs, vol. 2 : t. 159 (1855) [C.E. Faxon]