Notes on the Scientific Names Used At This Site
The scientific names used at this site were the ones used in the 1993 First Edition Jepson Manual until 2012, when I gradually began switching to the 2012 Second Edition Jepson Manual (JM2) names. Because I only update pages when I work on them again in the field, most of the pre-2012 pages will remain in the First Edition system until I return to them in the field. Pages in the JM2 system explicitly state that fact. All pages have their latest revision date at the bottom; dates prior to 2012 are still in the First Edition system.
Although the online Jepson eflora continues to be updated with new treatments and new names, with few exceptions I continue to use the names in the 2012 print version. The main reason is that if you have one of my lists in the field, and you are carrying the 2012 print edition, it would be impossible for you to look up any names that have been changed since that time. In contrast, if you are using the online Jepson eflora on your phone or tablet, you can still look up the older name since the site retains the synonyms of the names in one of the search functions (see below).
The exceptions are:
- When only the gender of the name has been changed (e.g., Nama demissum to Nama demissa), I usually will make that change since one can still figure out the name in the print version easily.
- When a new species has been described that was not in the print edition. Not finding that name in the print edition will alert users that it really is a new species, and not just a name change.
The links in our floras to the Jepson eflora treatment and Calphotos pix are updated to new names as necessary, even as the names themselves remain unchanged, since the Jepson eFlora does not retain the print edition treatment if it has been updated. For example, all Chamaesyce in the 2012 print edition have been changed to Euphorbia in the eFlora. I retain the name Chamaesyce in the floras here, but the links go to the Euphorbia eFlora treatments and Calphotos pages. Thus if you click on a link under one name, and you get the eFlora or Calphotos pix under a different name, that usually indicates that the name has been updated there.
The Calphotos links are often problematic. For some time after the 2012 Second Edition Jepson Manual, the Calphotos names remained unchanged (for example, when Chamaesyce was updated to Euphorbia in the eFlora, the photos at Calphotos remained under Chamaesyce for a considerable time. At some point, most of the Calphotos names were updated to the Second Edition name. Similarly, changes to newer eFlora names are not always made at Calphotos when the eFlora is updated.
This page gives the differences in scientific names used at this site from the Second Edition 2012 Jepson Manual (JM2) names.
General comments are given first, with comments on specific taxa in the order of clades as presented in the JM2.
- I use ssp. in the name instead subsp.. For reasons unknown to me, the long-standing convention to use ssp. was changed in about the year 2000 to use subsp. The longer version needlessly takes up more space.
In fact, I'd prefer it to be dropped altogether, in favor of just using a trinomial. After all, we don't need to have a prefix before the specific epithet. i.e., the name Chilopsis linearis ssp. arcuata would be just as clear, and arguably clearer, if it were written Chilopsis linearis arcuata. A bonus would be that the rampant confusion about the difference between variety and subspecies would then disappear.
Although some botanists like to use ssp. to apply to taxa that have more differences from each other than ones to which var. is applied, in practice there is no such difference:
- Jepson, in his 1925 Manual, used only variety. If the name didn't already exist under var., he simply made a new combination.
- Munz, in his 1959 California Flora, p. 20, wrote:While in our own monographic work we tend to use of subspecies, we feel that such monographic treatment of various groups of plants is now so uneven that we are in no position to make the hundreds of new combinations necessary for consistency.
- In the JM1, Arenaria macradenia had two subtaxa listed as varieties, along with one listed as a subspecies.
The arguments seem pretty strong for just dropping the prefix before the third part of the scientific name.
- Although the convention is to italicize only the names of taxa, and not the var. or ssp. in their name, it is infinitely easier for me to italicize the entire name due to the process of putting names in a computer database onto the web. Thus instead of the conventional Chilopsis linearis ssp. arcuata, I use Chilopsis linearis ssp. arcuata. This difference would become moot if we dropped the ssp. and var. part of the name.
It is also a bit jarring mentally to have the switch between italics and non-italics within the name itself, so italicizing the entire name makes plant lists more readable, since it keeps the entire name in the same font.
Pteridaceae, Notholaena californica. I use the two reserved-judgment taxa mentioned in the JM2, ssp. californica and ssp. leucophylla, which are dramatically different in the color of the back of their leaves. So far there seems to be no difficulty in assigning a given specimen to one of these subspecies.
Asteraceae, Eriophyllum wallacei var. rubellum. This reserved-judgment taxon in the JM1 is not even mentioned in the JM2. Yet var. rubellum, with white ligules and a coherent geographic distribution, seems to be a much more valid taxon than many others. It also causes considerable confusion by not being explicitly called out, with many excellent botanists mistaking this taxon for E. lanosum.
Chenopodaceae, Atriplex lentiformis ssp. lentiformis. This is a reserved-judgment taxon in the JM2, which distinguishes this from the insular ssp. breweri, which has larger leaves and fruits. See the note here.
Papaveraceae, Eschscholzia minutiflora ssp. minutiflora. This is a reserved-judgment taxon in the JM2, clearly distinguished from the other subspecies which have dramatically-larger petals. Calling it out separately also allows a much simpler key to separate it from E. parishii in the Anza-Borrego Desert. Many people in the Anza-Borrego Desert have been confused by trying to use the leaves to separate these taxa, whereas all it takes is a glance at the petal size.
Saxifragaceae, Heuchera elegans, H. caespitosa. These species were separate until the JM2, when they were lumped under the older name of H. caespitosa. I continued to use the separate names, since the plants in the San Gabriel Mountains had long been called that name, and the plants were so strikingly beautiful, the showiest of the Heuchera species, truly elegant compared to other Heucheras.
Soon afterward, in November 2013, I heard from Ryan Folk, who was working on Heuchera for his dissertation, who wrote that he was surprised these two species were lumped together since they were "distinguishable by morphology and chromosome number". See H. caespitosa and H. elegans.
The FNA treats them as separate species, distinguishing them by the shape of the hypanthium and whether the sepals are unequal or not in the key. The descriptions give different lengths of the petals, 3-4 mm for H. elegans, and 2-2.5 mm for H. caespitosa, making H. elegans more showy by a factor of 2.2 to 2.5, since the area of the petals scales with the square of the length.
Hence I am preserving them as separate species in my lists. One can always lump them later if they are separated now, but it takes a lot more work to separate them if one lumps them.
As of 2013, the vast majority of vouchers were still called H. elegans (155), not H. caespitosa (5). Although by 2018 some botanists have started calling the SnGb plants H. caespitosa, there are still more vouchers online called H. elegans, 181 to 50.
Tamaricaceae, Tamarix chinensis and T. ramosissima. I subsume Tamarix chinensis under T. ramosissima since the vast majority of the time I do not see flowers that would allow me to discriminate these species. These two species are extremely similar except for minute details of the flowers. In fact, the most common plant in this U.S. invasion is a hybrid combination of two species-specific genotypes that were geographically isolated in their native Eurasian range (Gaskin and Schaal 2002).
Juncaceae, Luzula comosa. I retain this name for the plants in southern California formerly ubiquitously called by this name, even though the JM2 treatment didn't call the plants in southern California by ANY name. Instead, the JM2 treatment said, in the treatment for Luzula comosa:Pls from SnGb, SnBr, SnJt need further study.
Unabridged note: Many literature records may belong to Luzula subsessilis, particularly those from the south.
Poaceae, Bromus madritensis. Most of the time, I lump ssp. madritensis in with ssp. rubens.
Poaceae, Hordeum murinum. I don't bother trying to identify this species to the subspecies level. The subspecies here, outside of its native range where they may be geographically separate, seem problematic, since the subspecies may be interbreeding here, and the distinctions are subtle.
Poaceae, Schismus arabicus / Schismus barbatus. I call all of these non-native plants S. barbatus without checking to see if any of the plants might fit S. arabicus. Life is too short to spend time looking at these weeds in detail for the determination, and 90% of the time I see these plants in the field, they do not have inflorescences that are necessary to distinguish them. Furthermore, it isn't even clear how our plants relate to the original species, since they almost surely have been interbreeding here, creating new forms that bear no resemblance to the original species. In fact, the Jepson Manual author no longer considers these as separate species in the western U.S., and now treats them as varieties of S. barbatus. See also this discussion and plot.
Copyright © 2012-2018 by Tom Chester
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
Comments and feedback: Tom Chester
Last update: 22 May 2018