An interesting question came up recently: What are the proportions of annual and perennial taxa in the plant diversity of the northern Chihuahuan Desert?

I have appropriate data from the BLM Las Cruces District—Doña Ana, Grant, Hidalgo, Luna, Otero, and Sierra counties, New Mexico—in the form of 4324 plant species richness plots. Most plots are circles with a 10m radius. The average number of taxa per plot is 18.5 and there are a total of 80,079 plant observations in the dataset. About 1280 taxa are represented, most at the species rank but with some varieties, subspecies, genera, sections, and subgenera. 30% of the taxa are annuals and 30.5% of the plant observations are annuals. Since the detection of annuals is much more dependent on season and recent precipitation than is detection of perennials, I think this is probably an underestimate relative to what the data would indicate if all plots had been visited under ideal conditions. How large that effect is I do not know, but if I had to guess, I think 35-40% of the observations would be annuals under ideal conditions.

Allium nevadense is, for the most part, a straightforward and easily recognized species. It has a single, terete leaf, often becoming slightly coiled distally, and white flowers. The tepals are widely spreading, lanceolate, entirely white or occasionally slightly pinkish, sometimes with the midrib a little darker. The stamens are ascending, a little shorter than the tepals, with anthers usually pale pink to yellowish, occasionally darker and reddish. The ovary is prominently crested and pale pink, white, or pale greenish-white.

Going by a 1992 paper by McNeal along with the Jepson eFlora and Flora of North America, Allium atrorubens var. cristatum can be distinguished from Allium nevadense by bulb coat features and by having erect, pale pink, dark-veined tepals. Some Allium atrorubens var. cristatum fits this description admirably. The flowers may be as pale as Allium nevadense when they open but quickly darken afterward. These plants are trivial to distinguish from Allium nevadense. As you can probably guess, some Allium atrorubens var. cristatum looks very much like Allium nevadense and is difficult to distinguish. These plants seem to be most often observed around the White Mountains. We could probably rely on geography to resolve this—but, as mentioned previously, that’s not any fun.

There is still a difference in the angle of the tepals and stamens between Allium nevadense and these troublesome individuals of Allium atrorubens var. cristatum, but it is subtle and I doubt it is reliable in practice. McNeal suggests we might look at the crests of the ovaries, deeply notched apically (i.e., near the style) in Allium atrorubens var. cristatum, usually not deeply notched in Allium nevadense. The ovary crests of Allium are often obscured or difficult to make out in photographs, but the open flowers of these plants make it easier. Of a half-dozen observations of Allium nevadense on which I could make out the crests reasonably well, all appeared deeply notched. Perhaps I could make out a distinction with the two in hand and a microscope, but the brief trial with photographic observations was not encouraging. However, I noticed a much easier feature that appears to be reliable. Allium nevadense has a green nectary ring between the ovary & bases of the filaments and the bases of the tepals. Unless a photograph is particularly oblique—not encouraged by the geometry of these plants—it is apparently always visible. In Allium atrorubens var. cristatum there is no nectary ring—or, at least, none that I can make out in any of the photographs available to me.

So, there you go. If the tepals are erect and pinkish, it’s Allium atrorubens var. cristatum. If the tepals are spreading and white or very pale pink, check for a green nectary ring. Allium nevadense if present, Allium atrorubens var. cristatum if absent.

When exploring the diversity of a genus I’m familiar with (Allium) in a place I’m not (California) it is, of course, reasonable to start with the low-hanging fruit. And so it is that I saw a couple of observations labelled Allium abramsii and thought to myself, “Well, that looks like a species I can’t get wrong, let’s go through the iNaturalist observations identified as Allium abramsii, as well as the other Allium from the same area, and see if we can correct some observations.” Not long after, I encountered some observations like this one and this one. Obviously not Allium abramsii, so what species is it? I ended up at Allium fimbriatum, but was not very confident. Over the next couple of days, I gradually realized that I had made an error—these plants are not Allium fimbriatum, but I couldn’t find any other plausible candidate. Eventually, only one plausible hypothesis remained: in the existing treatments of Allium in California, both of these species are called “Allium abramsii”.

Some further investigation revealed that the type of Allium abramsii belongs to the second species I encountered. My “Allium fimbriatum”, then, is the true Allium abramsii. The other plant is either an undescribed species or a species that had been described but then (mistakenly, I think) obscured in synonymy. I checked the Consortium of California Herbaria and SEINet for type specimens that might belong to this species. Then I checked the Flora of North America and Jepson’s A Flora of California for names that might apply to it. I didn’t turn up anything, though my search is not yet as thorough as it should be. Pending further developments, I believe this is an undescribed species. We’ll call it “Allium cf. abramsii” for the moment. Here are the observations on iNaturalist that I’ve found for Allium abramsii and Allium cf. abramsii and a couplet that distinguishes the two:

Margins of the inner tepals ragged-denticulate in the distal (widely spreading) half; flowers red-purple, usually ± concolorous throughout, sometimes paler toward the center of the flower when viewed from the front and toward the base of the erect, ± tubular portion of the perianth when viewed from the side; plants of the southern Sierra Nevada north of Granite Gorge to near Mammoth Lakes and Wawona . . . . Allium abramsii
Margins of the inner tepals crispate in much or all of the distal (widely spreading) half; flowers blue-purple to lavender, usually much paler toward the center when viewed from the front and toward the base of the erect, ± tubular portion of the perianth when viewed from the side (rarely, in plants with darker flowers, more or less concolorous throughout); plants of the southern Sierra Nevada, south of Granite Gorge to the vicinity of Bald Mountain . . . . Allium cf. abramsii

There may be other characters separating the two but the difference in color—unfortunately, always problematic given the inadequacies of our spectral vocabulary—and the crispate margins of the inner tepals are the obvious and eye-catching features in photographs of the plants. The crispate margins of the inner tepals also serve to easily separate Allium cf. abramsii from Allium denticulatum, to the south.

This is a case where both the advantages and disadvantages of working from digital images of live plants rather than from herbarium specimens become apparent. There are plenty of limitations when working from photographs. The inability to measure parts, to look at them under magnification, and even to see them if they don’t happen to be within the frame are probably the most obvious and universal limitations. In Allium, features of the bulb coat have played a central role in prior taxonomies, and this is entirely invisible except on the rare occasions when someone has photographed the bulb coat under a microscope. There are also advantages. In photographs, I find Allium cf. abramsii to be one of the most distinctive and easily recognized Allium in the western United States. So long as a photograph is clear enough to tell if the inner tepal margins are crispate, it is impossible to mistake it for any other taxon. In herbarium specimens, the differences between the two can be seen but are subtle. That it has not been named is evidence enough of this! In the Flora of North America treatment, McNeal mentions that the margins of the inner tepals are sometimes crispate but apparently attaches no particular importance to variation in this feature. The ability to look at a set of observations at once and in geographical context is also very helpful. Were I looking at the same set of plants as herbarium specimens, it probably would have taken me a while to work out that the two forms are allopatric, if it came to my attention at all. On iNaturalist, all it takes is applying some label to sort observations into the two groups and the geographic pattern is obvious.

I think I will likely publish a name for Allium cf. abramsii, though I don’t know what name I might give it. I would feel silly naming a plant I have not seen in person, so I hope to make a trip to see it in the field in 2023—and I will need to describe the bulb coat, of course! I’ve made an initial pass through herbarium specimens that have online images, and arrive at the following list for Allium abramsii: Fresno County: Hall & Chandler 201, 15-25 June 1900 (TYPE! CAS, MO, NY, UC, US); Cole 30, 17 June 1972 (CSLA); Holland s.n., 16 May 1965 (OBI); McNeal 3147, 26 May 1986 (BRY, UT); McNeal 3707, 29 May 1986 (BRY, UT); Morton 2815, 4 July 1941 (US); Stebbins s.n., 15 May 1985 (FSC). Madera County: Constance 2389, 1 July 1938 (NY). And for Allium cf. abramsii: Kings County: Clifton 13928, 28 March 1986 (PUA); Gill 80, 4 April 1959 (UCSB). Tulare County: Baker 7334, 30 May 1974 (LOB); Ganley 721, 18 June 1971 (MACF); Haultain s.n., 13 July 1995 (THRI); Keil 18835, 15-16 June 1985 (OBI).

We continue my series of more and less exasperated criticisms of the Jepson eFlora and Flora of North America treatments of the genus Allium with an entry that is more. Here’s the FNA couplet separating our protagonists:

95 Leaf blade strongly falcate; umbel mostly 5–10-flowered . . . . Allium parvum
95 Leaf blade linear or weakly falcate; umbel 20–30-flowered . . . . Allium cratericola

And the Jepson eFlora couplet (I’ve expanded the geographic abbreviations in the original):

41. Leaves straight or ± sickle-shaped; flowers 20–30; Klamath Ranges, North Coast Ranges, Sierra Nevada Foothills, southern High Sierra Nevada, Tehachapi Mountains, Inner South Coast Ranges, Western Transverse Ranges, San Jacinto Mountains ….. Allium cratericola
41′ Leaves sickle-shaped; flowers generally 5–10; Klamath Ranges, High Cascade Range, High Sierra Nevada, Great Basin ….. Allium parvum

The situation is complicated because Allium parvum is conspicuously heterotypic. I don’t know how many species are included in Allium parvum in these treatments, but the number is at least three. Let’s tackle geography first, because that’s easier. The “Allium parvum” in the Klamath Ranges and High Cascade Range is probably some subset of the Allium falcifolium / Allium siskiyouense complex, likely the white-flowered plants that I am provisionally including under Allium siskiyouense. The High Sierra Nevada Plants are… I don’t know what they are but they look like this. I have a hunch that they’re affiliated with Allium burlewii. If there isn’t a published name for them, there should be. I might look into that one more later.

That leaves the Great Basin plants. There’s a set of morphologically homogeneous observations in a polygon approximately bounded by—starting at the south and moving clockwise—Topaz Lake, Truckee, Susanville, Summit Lake, and Fernley. Kellogg’s protologue for Allium parvum mentions plants from Mount Davidson and Washoe. Kellogg’s specimens, unfortunately, were probably lost in the 1906 San Francisco fire, and I haven’t yet found a neotypification of Allium parvum. “Washoe” presumably refers to Old Washoe City, Washoe Valley, or an adjacent site. I believe “Mount Davidson” is the Mount Davidson in Storey County, Nevada. These sites are within the polygon described above, and all the observations around Washoe Valley and Mount Davidson that might be called “Allium parvum” seem to belong to this homogeneous grouping of Great Basin plants. So, the Great Basin plants are presumably Allium parvum.

We can simplify the geography a bit: Great Basin—and probably some distance into the lower elevations of the north end of the Sierra Nevada—is Allium parvum, anywhere else is Allium cratericola. Judging by the numbers of iNaturalist observations, Allium parvum appears to be reasonably common around Reno, and presumably in similar but less populated habitats along the east base of the Sierra Nevada, but rarely observed in California. The High Sierra Nevada and Klamath / Cascade plants are also infrequently observed in California, though more often than Allium parvum. You can find iNaturalist observations of Allium cratericola here, and I’ve aggregated a set of observations of Allium parvum sensu stricto here.

For the pragmatic task of differentiating the two, we have a clear & easy geographic distinction and we could just stop there. But that wouldn’t be any fun, would it?

Imagine a linear, flat leaf. It is arcuate if it is curved in a plane more or less perpendicular to the wide axis of the leaf’s cross-section. It is falcate if it is curved in a plane more or less parallel to the wide axis of the leaf’s cross-section. The leaves of both Allium cratericola and Allium parvum are arcuate and not, or only weakly and inconspicuously, falcate. The leaves of Allium parvum sometimes look falcate from a distance but, on closer examination, are arcuate and twisted—the distal portion of the leaf is curved in a plane parallel to the ground and perpendicular to the wide axis of the leaf’s cross-section. Only a few Allium parvum appear to actually have falcate leaves. The “falcate or not” distinction in the key will work approximately none of the time.

There does appear to be a difference in the average number of flowers per inflorescence. It doesn’t look consistent enough to differentiate the two species reliably, but this part of the key will work the majority of the time.

There appears to be a consistent difference between the two in leaf width: wide and often truly flat in Allium cratericola (sometimes variable among leaves of a single plant, but at least one of the leaves wide), narrow and always channeled (U-shaped in cross-section) in Allium parvum. One of the limitations of using iNaturalist is that I can’t measure the leaves, so I can only say “wide” and “narrow”, but there is a pretty obvious and apparently consistent difference between the two. The difference disappears if we adopt the heterogeneous circumscription of Allium parvum, though—the leaves of both Allium siskiyouense and the mystery entity in the High Sierra Nevada are wide. Those two also have falcate leaves, as it happens, making the “falcate or not” actively misleading rather than merely uninformative—Allium parvum sensu stricto falls on the “cratericola” side of the line.

Anther color is informative some of the time. Allium parvum has purplish anthers, while Allium cratericola has yellow or purplish anthers. The variation in Allium cratericola may warrant some further exploration. The observations of this species in iNaturalist occur in five population clusters: in the northern Coast Ranges; around the west base of the northern Sierra Nevada (centered on Table Mountain); around the west base of the central Sierra Nevada (mostly east of Stockton); around the Tehachapi Mountains; in the San Jacinto Mountains. The northern two, in the northern Coast Ranges and around Table Mountain, have purplish anthers. (There are occasional plants with the flowers entirely unpigmented, but apparently none with yellow anthers and the typical pinkish color & dark midribs of the tepals.) The remaining three, east of Stockton, around the Tehachapi Mountains, and in the San Jacinto Mountains, have yellow anthers. There seem to be some other subtle differences between these two groups, as well, though nothing I can easily put my finger on at the moment. It might be worth recognizing two taxa, at least at the varietal level. Although anther color alone doesn’t seem like an especially significant character, the differentiation is cleaner than the boundaries between many species of Allium in California. The geographic isolation between these population clusters also implies some degree of reproductive isolation, although we should suspect that all five are pretty well isolated from each other under current conditions. I also note, without further comment, that the FNA description for Allium cratericola simply says “anthers yellow”.

I omit a couplet for this entry. One remaining difficulty is that, while I think I have a reasonable idea what the form of Allium parvum in northwestern Nevada and adjacent California looks like, and this form seems to be the relevant one in the context of distinguishing Allium cratericola and Allium parvum, I definitely do not understand Allium parvum as a whole. In any case… just don’t use the “falcate or not” character, OK? Use geography if you merely want to put names on plants. Use a combination of leaf width, number of flowers, and anther color if you want to do it the hard way.

One last, minor detail: I think the inclusion of the southern High Sierra Nevada for Allium cratericola is simply an error. Neither the Consortium of California Herbaria nor SEINet have herbarium specimens of Allium cratericola, and I can find nothing on iNaturalist that would plausibly be included in the species. Populations in the western Transverse Ranges and south Coast Ranges, on the other hand, are missing from iNaturalist but documented by herbarium specimens.

I’ve been trying to understand these two species via iNaturalist observations, and at this point I’ve at least been looking at them long enough to have an opinion. Here’s the couplet distinguishing them in the Jepson eFlora:

45. Leaves generally 6–8 mm wide; perianth parts 9–15 mm, long-acuminate . . . . Allium falcifolium
45′ Leaves < 6 mm wide; perianth parts 6–10 mm, obtuse to acute . . . . Allium siskiyouense (among others)

The Flora of North America key is similar, leaving leaf width out in favor of the somewhat unhelpful “tepal apex […] inner margins usually denticulate” vs. “tepal apex […] inner margins denticulate or not”. (And, no, I don’t know which side of the tepal apex is “inner”; I think “margins of the inner tepals” is meant, if not written.) For distinguishing these two—and leaving the “others” aside—this leaves room for improvement. The problem is that Allium falcifolium has considerable variation in tepal shape, even in areas where it is reportedly the only species present and confusion with Allium siskiyouense should not be an issue. Some plants have lanceolate tepals with exceptionally long-acuminate apices. The tepals in such plants are erect in the proximal half or so, forming a narrow tube, and widely spreading the distal half or so. Some plants have urceolate flowers with lanceolate tepals that have acuminate apices, only moderately spreading for a short distance. Most plants are somewhere between those two extremes. Tepal color is also variable. The majority of plants have purple tepals, as those linked in the prior sentences, ranging from dark purple to somewhat lighter and often more reddish purples. However, they can also be various shades of pink or lavender, and sometimes quite pale. They can be white, sometimes with darker midribs. Rarely, they may even be red, or whatever color this is.

Allium falcifolium is also the more widespread and frequently observed of the two, by a wide margin (I’ve got about a 20:1 ratio between the two in iNaturalist observations). It’s reasonable to look somewhere in all that variation for a distinction between “long acuminate” and “obtuse to acute” tepals. And, indeed, there are plants with long-acuminate tepals, plants with obtuse tepals—often, these are plants with the tepals acuminate but not dramatically so, the tepals gradually narrowing for some distance before, I guess, giving up—and plants with acute tepals. However, while it is easy to find plants that are on either side of the line, if you try to systematically separate them into two categories, you’ll eventually give the task up as hopeless—but not before noticing that no matter where you put that line, plants on the “siskiyouense” side of it extend throughout the entire range of Allium falcifolium and far from the reported range of Allium sikiyouense. I suspect most people have tried to assign the name “Allium siskiyouense” to plants on the more obtuse / acute end of this spectrum within and extending some distance beyond the reported range of Allium siskiyouense, before deciding at some distance that the plants must all be Allium falcifolium no matter what the tepals are doing.

All that said, this is what I think Allium siskiyouense actually looks like. Flowers narrowly campanulate, tepals narrowly elliptic, apex obtuse to broadly acute, usually pink with somewhat darker midribs, occasionally purple, occasionally white. At least, plants that look like this are the only way I can end up with a circumscription of Allium sikiyouense that is consistent with the keys and descriptions in the Jepson eFlora and Flora of North America, is consistent with the distribution maps of those two resources, and yields two taxa that are more or less reliably identifiable (there are still exceptions and problems, but these do not appear to be optional features). So, here’s a couplet that may work:

Tepals lanceolate to linear-lanceolate, the apices acuminate (sometimes dramatically long-acuminate), sharply acute, or both; margins of the inner tepals usually denticulate; flowers urceolate to salverform, usually somewhat constricted around the height of the anthers; leaves generally 6–8 mm wide . . . . Allium falcifolium
Tepals narrowly elliptic, the apices obtuse to broadly acute; margins of the inner tepals usually not denticulate; flowers narrowly campanulate, not at all constricted; leaves < 6 mm wide . . . . Allium siskiyouense

I can’t measure leaves in iNaturalist observations, but they do appear to be wider in Allium falcifolium, at least on average. I can make out denticulate margins on the inner tepals of a lot of Allium falcifolium observations and only a couple of Allium siskiyouense observations, but this isn’t a feature that tends to show up well in photographs.

You may be wondering at this point—”OK, but with all the variation in Allium falcifolium, is that really a species?” I don’t know. At present, I’m not able to see patterns in the mess of variation that would allow it to be divided into coherent taxa. I would not be at all surprised to learn that such patterns exist, though.

I’ve been confused by the distinction between these two species for a while. I find existing keys unhelpful. Here’s the relevant couplet from the current Jepson eFlora key:

30. Leaves generally withered in flower; perianth red-purple, rigid-keeled, ± shiny in fruit, tip margins inrolled, parts with a purple crescent adaxially just above base — Allium campanulatum
30′ Leaves generally not withered in flower; perianth white or pink to rose-purple, not keeled, papery in fruit, tip margins ± flat, parts without darker crescent adaxially — Allium bisceptrum (and Allium membranaceum)

And the couplet from the Flora of North America:

58 Leaves usually beginning to wither from tip by anthesis; tepals rigid (not papery), ± shiny in fruit, strongly involute at tip, carinate. — Allium campanulatum
58 Leaves usually green at anthesis; tepals papery (not rigid and shiny) in fruit, not strongly involute, not carinate. — Allium bisceptrum (and Allium membranaceum)

Taking the characters from the two keys in order, my impression is:

Leaves withering by flowering: There may be a difference in averages between the two, but if so I can’t tell. Certainly both frequently do have leaves withered by flowering.

Perianth color: There definitely is a difference in averages, with Allium campanulatum usually darker. However, there is too much overlap for this to be reliable.

Perianth rigid-keeled, ± shiny in fruit vs. not keeled, papery: I can not make out any distinction between the two in this feature.

Perianth margins involute vs. flat toward the tip: I can not make out any distinction between the two in this feature.

Tepals with or without a dark crescent near the base adaxially: Allium campanulatum almost always has this crescent, Allium bisceptrum has it perhaps half the time.

My experience of the two is almost entirely via images on iNaturalist. It’s entirely possible that these are all good features on herbarium specimens, and simply do not work well, or are difficult for me to interpret, on live plants. Nonetheless, I find only one of these features useful (the dark crescent on the tepals), and that one only partially. Yesterday, though, I was looking at some iNaturalist observations from areas where only Allium campanulatum should be present, and areas where only Allium bisceptrum should be present, and noticed some other differences that are much more evident and useful to me when looking at pictures of live plants. Geography is, of course, also useful, although relying on it tends to raise suspicion that one is not distinguishing meaningful taxa. I summarize my current understanding in the couplet below:

Stamens remaining straight and erect throughout development; ovary crests dark green; pedicels green, strongly contrasting at the receptacle with the pink to whitish bases (abaxial surface) of the tepals; tepals with or without a darker band near the base (adaxial surface); plants of the east base of the Sierra Nevada and eastward in Nevada, Idaho, Utah, Arizona, and the western edge of New Mexico — Allium bisceptrum
Stamens appressed to the petals before dehiscence, curling over the ovary after; ovary crests dark red; pedicels not strongly contrasting with the bases (abaxial surface) of the tepals at the receptacle, usually purplish or grayish, if green then the bases of the tepals also somewhat greenish; tepals with a darker band near the base (adaxial surface); plants of the Sierra Nevada, south to the transverse ranges, and north through northwestern California and central Oregon — Allium campanulatum

Linked are some typical Allium campanulatum, as well as some typical Allium bisceptrum.

The stamens seem to be the most reliable character, if visible in the available pictures. The tepal crescent is useful when absent, otherwise uninformative. The other two seem to work the majority of the time, but neither seems reliable on its own. One might give stamens two or three times the weight of these two, the tepal crescent the same weight when absent, and treat the set of characters as a vote in which unanimity is pleasant but not necessarily expected. There are still some plants I can’t confidently assign to either species, though, and the color features entirely fail in central Arizona, where Allium bisceptrum is dark-flowered.

Patrick’s Unique Identifier Dictum (PUIDD): If you need to assign unique identifiers in order to differentiate two records in a database, you don’t need to differentiate those two records in that database.

(No, this is not always true. I think the ratio of how often it is true to how often informatics people believe it is true, though, is very high. It’s at least worth asking what a UID is intended to accomplish in any particular case, rather than assuming that they are universally desirable.)

Certainty is an epistemic attitude, acting as if the error rate in one’s knowledge is zero. A desire for certainty, then, runs against a desire for understanding.

Consciousness is a retrospective simulation of one’s own mental state.

If you ever work with nomenclatural databases, you will find that a few little Latin words, usually abbreviated, become the bane of your existence: “auctores (auct.)”, “hortus (hort.)”, “non”, “sensu”, “ineditus (ined.)”. All of these are ways of saying, “Yes, I know that this field is labelled ‘scientific name’, but I’m going to put things in here that aren’t valid names and let you try to sort it out.” Something like “Festuca cinerea auct. non Vill.” is a way of saying, “Some botanists are using the name Festuca cinerea in a way that I think is inconsistent with the typification / diagnosis given by Villars”. In other words, someone misidentified some plants. However, when someone puts the name “Festuca cinerea Vill.” on an herbarium sheet, if the plant is not in fact “Festuca cinerea Vill.” then they have simply made an error. They have not created the new name “Festuca cinerea auct. non Vill.” so don’t put that in your nomenclatural database. Or, at least, put it somewhere other than a field that’s supposed to contain names, because this is not a valid name under any of the nomenclatural codes. It can be very useful to keep track of misapplied names in regionally important floras, as a way of indicating where and why past botanists are likely to apply a name to plants in a way that might be otherwise inexplicable. That’s great. Misapplication and misidentification are not nomenclature, so find a good home for it where we won’t think it’s nomenclature. Create a data structure that makes this distinction, and use it.

Much of this stems, I think, from the historic expense of paper and typesetting. As you move further back in the botanical literature, manuscripts get denser and more abbreviated. The reader is expected to infer a lot from changes in font size, indentation, italicization, and spacing. If something looks like a name, is italicized without a latinate ending, and is followed by a number or a date, that’s probably the citation of a type specimen. Of course you know what book would be abbreviated “Ber. Deutsch. Bot. Ges.” because there just aren’t that many botanical works published. Writing “auct. non L.” is a lot more compact than writing out that some authors have applied this name contrary to Linnaeus’s intent, and your reader will know that this is shorthand rather than a new botanical name. But now we have various databases that originated largely by turning this compact and abbreviated style into digital data. Something you can easily infer when reading one entry becomes a colossal mess once you put 100,000 of those entries in the “name” field of a database. The data need to be made explicit rather than left to inference. So, sure, “Festuca cinerea auct. non Vill.” is fine in a 19th century manuscript. Maybe even in a 20th or 21st century manuscript. It does not belong in a database and especially not in a “name” field.

Well, to be honest, I wouldn’t mind if we banished “auct.” entirely. “Hook. non Vill.” at least tells me something potentially useful–that I should expect Hooker’s application of a name to be different than that of Villars. “Auct. non Vill.” tells me nothing. Some unspecified author(s) somewhere misapplied the name. What am I supposed to do with that? I’ll never know when I’m encountering “Festuca cinerea auct. non Vill.” rather than just “Festuca cinerea Vill.” People don’t knowingly and intentionally misapply a name and then helpfully point this out for you. “Auct.” is someone else–unless, perhaps, someone is setting you up for a particularly obscure form of the Liar’s Paradox.