Is this the same as Hierochloe odorata ?

Depends on which taxonomist you believe. With that in mind, the source we generally follow for the ATP database lists Hierochloe hirta as a synonym of Hierochloe odorata. So, yes, they are the same plant. More or less.

Thank you, Kent -- although, I must be missing something; where does the DB list it as a synonym? When I search "Hierochloe hirta" it shows nothing found, and when I look at the entry for Hierochloe odorata I don't see where it is shown as a synonym.

I confess that the DB sometimes mystifies me...

We usually add synonyms only when we have an existing entry for the synonym and have to delete it, or when someone proposes a new plant and we learn that it's a synonym of a plant with an existing entry. In other words, we add synonyms when we know that people might be looking for those names.

It doesn't.

The database was never intended to include a comprehensive list of synonyms. It would be a Herculean task to add them all and, in most cases, not particularly valuable. Hierochloe odorata, for example, has around 50 synonyms. Consequently, synonyms mostly get added when questions or issues like this arise (I'll add hirta here shortly).

Oops, cross posted with zuzu

KentPfeiffer said:It doesn't.

The database was never intended to include a comprehensive list of synonyms. It would be a Herculean task to add them all and, in most cases, not particularly valuable. Hierochloe odorata, for example, has around 50 synonyms. Consequently, synonyms mostly get added when questions or issues like this arise (I'll add hirta here shortly).

Thanks for that explanation (and thanks to Zuzu, as well) -- when I looked back at your original answer I saw where I got confused; you wrote "the source we generally follow for the ATP database lists Hierochloe hirta as a synonym of Hierochloe odorata. " Somehow my brain missed the first part and just saw " the ATP database lists Hierochloe hirta as a synonym of Hierochloe odorata. "

No problem.

As an aside, there has always been tension in the world of taxonomists between "lumpers" and "splitters". Lumpers generally argue for fewer numbers of species (and, as a result, greater variability within a given species) whereas splitters prefer to acknowledge that variability by recognizing more species. In the past decade or so, DNA testing has become inexpensive enough to be used by plant taxonomists. For the most part, these tests have allowed the lumpers to have their way. I'd guess, as the tests become more sophisticated, the splitters will get their chance soon.