What does the L stand for?

"Bromus L. of North America" is Leon Pavlick's magnum opus, illustrated by the indefatigable Elizabeth J. Stephen with some back-up from Peggy Frank and the fabulous J.R. Janish.

According to the back matter, which I assume is not exaggerating in the slightest, this taxonomic work is the first comprehensive treatment of North American bromegrasses since 1900. Anyone concerned with grasslands in North America (or grasses in general) should find this book useful and informative.

Indeed, "Bromus L" is a kind of field guide or at least identification guide, with keys, range maps, black-and-white line drawings, even vernacular names (thanks!). These include Field Chess, Rattlesnake Chess and Rescue Grass. No thanks?

In bromegrass-interested circles, the term "North America" apparently only refers to Canada and the United States, i.e. North America north of the Rio Grande.

So what *does* the L stand for, then? Here's a guess. "Leon" as in Leon Pavlick?