Annual pennyroyal could just as well be called annual lemonyroyal
Hedeoma acinoides, known as annual pennyroyal, could just as well be called annual lemonyroyal because the plant’s foliage has a pronounced scent similar to that of lemons. Whether at least some of the same chemicals that account for that aroma in lemons are at work in this pennyroyal species, I don’t know. I do know that this photograph is from April 12th along the right-of-way west of Morado Circle. If you’d like a closer look at one of these diminutive flowers, which barely reach half an inch in length, you can have one.
© 2019 Steven Schwartzman
Portraits of Wildflowers 
‘Pennyroyal’ sounds like it belongs in a nineteenth century British novel: perhaps attached to a down-at-the-heels, social climbing member of the underclass.
The combination of ‘penny’ and ‘royal’ in the genus name amused me. Neltje Blanchan recently solved two naming mysteries for me, so I thought perhaps she would solve this one, but not so. On the other hand, her entry on H. pulegioides (page 47) does include the tidbit that “herb gatherers who collect our pennyroyal, that is so similar to the European species…say they can scent it from a greater distance than any other plant.”
shoreacres
May 4, 2019 at 7:37 AM
I can’t smell pennyroyal even if I’m standing up right next to one of these low plants. In contrast, it’s not unusual for me to sit down to photograph something else, never having noticed any pennyroyal, and then be alerted by the scent that some must be close by. On Thursday at the Wildflower Center we saw some Hedeoma drummondii and I noticed that its leaves have a similar fragrance.
As for the word, the American Heritage Dictionary gives this etymology:
Probably by folk etymology from Middle English puliol real, from Anglo-Norman : puliol, thyme (from Latin pūlegium) + real, royal (from Latin rēgālis; see REGAL).
Steve Schwartzman
May 4, 2019 at 9:17 AM
I had a friend who had a scented garden. I don’t think she grew this one but it would have been a nice addition. I’m fascinated by the success of annuals…I would think they would have a hard time competing against perennials. But of course, they are well adapted to take advantage of disturbed ground and could more easily shift their range to accommodate climate change.
melissabluefineart
May 4, 2019 at 9:01 AM
Inconspicuous this pennyroyal may be, but I can say for sure that what it lacks in size it makes up for in numbers, and that it thrives in my neighborhood every year at this time.
Steve Schwartzman
May 4, 2019 at 4:15 PM
I wonder if Pennyroyal is related to Moneypenny? We have a few pennyroyals in New England but not this one.
Steve Gingold
May 5, 2019 at 2:10 AM
Never having formed a bond with spy movies, I had to look up Moneypenny.
Your reference to pennyroyals in New England sent me to the BONAP maps at
http://bonap.net/Napa/TaxonMaps/Genus/County/Hedeoma
and I learned we have a couple of species here in Travis County that I was unaware of.
Steve Schwartzman
May 5, 2019 at 6:19 AM
Glad to be of service.
Steve Gingold
May 5, 2019 at 12:27 PM
One of my grandmothers, the gardener, sometimes used to scatter this on the floor, at the entryway to the kitchen, as an ant repellent. As kids, we thought it was great, to be handed some herbs and told to go throw them on the floor! She ran a pretty fun kitchen.
Robert Parker
May 5, 2019 at 12:21 PM
I’m glad to have brought back those happy memories for you. As a kid I used to spend plenty of time on the floor. Maybe all kids do. Maybe adults would too if floors were softer.
Steve Schwartzman
May 5, 2019 at 1:23 PM
One of my favorite eucalyptus trees is the lemon gum, which really does smell like lemon rind. (Irrelevant, but I do dig the aroma.)
tonytomeo
May 9, 2019 at 12:50 AM
You can continue to dig the aroma as long as you don’t dig the tree (up).
Steve Schwartzman
May 9, 2019 at 6:15 AM