Ionactis – an early Blue Ray Disc

 “Aster linariifolius is an easy-to-grow, un-aster-like eastern US native aster, which ranges from Canada south to Florida. Perhaps this is why the Evil Empire of Plant Taxonomy has now banished it to the Genus Ionactis.” Plant Delights website, commenting on their ‘Little Stiffy’ Aster.

The Back Story

There must have been something in the water at the end of the 19th century.  A new “Empire” of Botanists was breaking free from a previous generation of botanical philosophies regarding how plants were classified, particularly relating to the circumscription of genera.  In a post on Platanthera, I described how P. A. Rydberg approached native terrestrial orchids, in Oakes Ames’s words:  “Dr. Rydberg has gone further than any other author of modern times in the splitting up of the genus, and has given us several new segregate genera.  He is not at all in sympathy with the conservatism of Bentham and Hooker, Torrey, Gray, Cogniaux and others, and is much opposed to the maintenance of large groups which in any way may be divided.’.  

Rydberg was dedicated and energetic, describing 131 genera (reported in POWO, Kew’s Plants of the World Online) between 1896 and 1932.  He wasn’t alone, nor was he first.  Between 1887 and 1906, POWO reports Edward Lee Greene described 127 genera, concentrating on the Asteraceae.  In an earlier posting I described the Whitetop Aster, which Greene settled in the genus Oclemena in 1903. Here, I want to discuss his Ionactis, constructed to include our native Ionactis linarifolia and two Northwestern plants, Ionactis alpina, and Ionactis stenomeres.  

The current Flora of North America treatment assigns 5 species to genus Ionactis, 4 of which are native to Western North America (including Mexico), the exception being Eastern North America’s I. linarifolia.  This Ionactis distribution pattern mirrors that of its closest relative, Heterotheca (excluding Chrypsois).  Of the 44+ Heterotheca species, only H. subaxillaris is widely distributed in Eastern North America, the others being native to Mexico and Western North America.  If, over the long term, these assignments prove valid, we should consider Ionactis and Heterotheca as basically Western plants, each having one member that has broken out to widespread presence in the East.  

It makes sense that E. L. Greene would be the first to recognize Ionactis as a distinct genus, in that his first exposure to plant taxonomy was in the Eastern US, while his first lengthy research position was in Northern California, at UC Berkeley.  That cross-country transition would not be his first.  Exploring Greene’s publications, a colorful personality surfaces readily; reading comments of obituary writers and his professional colleagues bolsters the impression this was a retrospective, seemingly shy, scoffingly-humorous, and strongly opinionated man.  

J. N. Rose (who worked at Smithsonian and co-authored treatments on Crassulaceae and Cactaceae with N. L. Britton) wrote in 1916 (Botanical Gazette):

He was indeed a man of many moods and fancies; was often shy but never timid; always had many friends and many enemies. He was egotistical, sometimes to the point of being ludicrous, and yet to many of us who knew him well he was always a delight and an inspiration.”  

Willis L. Jepson (who compiled the on-going Flora of California) records W. R. Maxon (Curator of the U.S. National Herbarium) as saying: “Greene had one of the most delightful personalities that I have ever known – at any time, anywhere. He was wholly unique and individual. He loved to jest and I can so well remember his mannerisms. He would put his hand up his nose with the forefinger pointing upward, with a little grimace and say: “I have swallowed a canary!” Meaning that he had found a certain well-known West American botanist in error, as he viewed it, and had written a little note setting him right so that he might go forward by the right path ever after!”  Jepson ends with his own summary:

“It is my hope that it will help preserve the memory of a man who was every inch an individual.”

Greene had to have been driven and inexhaustible; he must have read voraciously, recalled every nuance, which meant he held strong opinions and had a lot to report.  An early outlet for his pen was Pittonia, a series of writings presented as a journal, gathered in 5 volumes between 1887 and 1905.  You can garner some flavor of Greene’s personality in reading his behind-handed explanation ‘Wherefore Pittonia?” (v.1, page 51).   In explaining the name of this collection, he gets in his “digs” and tells us:  “So then, the name that heads these pages is not newly counted; is far from being an original conception of the present writer.  And all this is well known to the few of our botanists who do not ignore the fact that there existed a botanical nomenclature before Linné.”  (see Appendix for a copy of the complete article.)

Living and working in California’s Bay area as an Episcopal Priest and a Botanist (oh, yes, you’’ll need to look Greene up in Wikipedia to get the tea on the Priest part), Greene set about compiling a regional flora, which required a bit of taxonomic maintenance.  Genera and species have to be officially published in printed journals to have legitimacy, and the sooner the better.  In Pittonia (vol 3, Part 17, printed and sold in 1897 for 50¢) Greene explains: “In finishing the manuscript for part IV of the Flora Franciscana, I found it necessary to propose a few new genera, and to restore certain others which had been ignored by American botanists of the last generation.”  

Without pausing to explain the reasoning behind his selection of a name (“Ion” for violet or blue; “actin” for ray or star) Greene launches right into defining the new genus Ionactis, the first of three species being I. linariifolia, a plant Greene bases on Aster linariifolius of Linnaeus, Chrysopsis linariifolia of Nuttall, Diplostelphium linariiifolium of Ness and Diplopappus linariifolius of Hooker.  Greene says of I. linariifolia, “One of the most beautiful of all North American asteraceous plants, and of the widest geographical range, being frequent occurrence from Newfoundland to Wisconsin and Texas.  All foreign authors, even the most careful and critical, seem to have believed it suffrutescent, having been misled by the hardness and rigidity of the stems in the herbarium specimens. …

There was, at least during his lifetime, acceptance.  Burgess (who contributed to the treatment of Composites in Small’s 1903 Flora) had this to say in his 1906 Discussion (italics are his):

“If we ignore the whimsical and universally rejected mésalliiance of Aster with Solidago and other genera by Kuntze in 1891, little alteration in the bounds of the consolidated genus Aster remains to mention, until the work begun in 1896 by E. L. Greene in his Pittonia , resulting in his separating or recognizing Doellingeria, Eucephalus, Machaeranthera, Tripolium, Helastrum, Oreastrum, Leucosyris, Leucelene and Ionactis.

“The limits for the genus Aster, which my own judgment approves are those adopted in Britton and Brown’s Illustrated Flora, in 1898, retaining two of Greene’s new genera, Luecelene and Ionactis, and recognizing Machaeranthera and Doellingeria as well as Sericocarpus and Brachyactis. My contribution of Aster-species to Small’s Southeastern Flora, 1903, also follows these limits. With the exception of the segregate genera named in this paragraph, Aster now includes in America nearly all the species which have ever been accredited to it; disregarding a few species which stood so near the debatable lines between Solidago, Aster, and Erigeron, that they had occasionally crossed over the lines in earlier times.”

Tradition held forth, such that much of the “splitting” by Greene and Rydberg was swept back into the closet, the historical genera (such as Aster and Habenaria) being restored. Recent systematists in certain groups have been mining those century-old circumscriptions for genera. Check the Appendix for more about Greene and his mostly losing battle with the “Empire.”

The Main Story

Ionactis is one of several “blue Asters” flowering in Spring and Summer here in the Apalachicola basin area, standing out most readily by its vegetative form and habit.  You’ll guess correctly that a blue-flowered daisy is Ionactis linariifolia if the plant is less than 18 inches tall, has short (under 2”) evenly-spaced, stiff and linear leaves that stand out perpendicular to the stem.  The plants are rhizomatous, so you’ll often find a modest colony of well-spaced rigidly upright stems in open spots along the forest floor. 

Each stem is topped initially, by a small head of pale yellow disk and blue ray flowers. If you bother to check under the hood, you’ll see the involucre is loosely multi-seriate, with narrow green outer phyllaries (bracts) and pale inner bracts that are fairly tight against the head.  Flowering leads to a pompom of tan fluff, generated by small, conical dark achenes (covered basally with long stiff ascending hairs) crowned by a significant pappus of tan capillary bristles, the outer bristles about as long as the achene, but the inner bristles 4-7 times that length.  The whole deal seems fashioned from a badminton birdie, with the pappus extending the conical shape of the achene.

As the season progresses, branching below the Spring termination generates another sequence of developing heads.  I haven’t had the experience of observing these plants over an entire season, or into the next, so a later emendation will have to explain how these very narrow-gauge stiff stems mature, and what happens with the passing of seasons.  I see no evidence of dried stems from last year, but my observations are from two locations that are burned regularly, so any evidence of dead bodies might have turned to ashes.

Given the distinct foliage, it’s unlikely people will confuse this plant with others in our region. Co-existing with Ionactis are the more common, shorter blue-flowered Asters,  Symphotrichum concolor (with two varieties) and S. adnatumSymphyotrichum concolor has ovate acuminate leaves and larger flowers with slightly more purple color to the rays and broader involucral bracts (that turn out and back in var. plumosa)  The S. concolor also develops larger basal leaves , is usually taller, and branches before flowering of the main stem.  In late June, in the exact same forested areas, we see Sympyotrichum adnatum coming into flower.  Though the flowering head is similar to Ionactis (including the tightly-appressed involucral bracts), this “Scaly-leaved Aster” is readily distinguished by small, ovate-acuminate leaves clasping the flowering stem.  The real issue with these two Symphyotrichums is not distinguishing them from Ionactis, rather dealing with plants that seem intermediate between the two.

Symphyotrichum concolor (left) and Symphyotrichum adnatum (right)
Symphyotrichum concolor v. plumosa
S. concolor v. plumosa involucre

There are yet other “Blue Asters” in our floral realm.  The most handsome, to me, is Symphyotrichum chapmanii.  This plant, however, is not to be encountered in drier forests, rather in boggy soils of our wet prairies.  The plant differs in so many regards from the other three species that I only mention it due to the striking stance and amply-sized blue-rayed flower heads, twice as large as those of Ionactis.  The 1.5 to 2.5 foot tall, lanky and distantly branched stems are as smooth as glass, bearing just a few long, grass-like leaves.  You’ll not confuse these two.

In fact, vegetatively, there are few possibilities for misidentification. Ionactis stands out as stiff, trim, and orderly.  The linear, short and stiff leaves are of an even spacing and length up the stem.  It’s a clean look; few shoots protrude from axils, until a few side branches emerge following initial flower formation.  You’d almost mistake the plant for a giant moss.  In our area, the only vegetative lookalike I encounter would be juvenile plants of Phoebanthus, which have longer, more widely-spaced leaves.  But indeed, there are curious similarities between these two, as though Ionactis is a blue-rayed, bonsai version of mature Phoebanthus specimens.

Foliage of Ionactis
Foliage of Phoebanthus juvenile


Linnaeus, C.  1753.  Species plantarum : exhibentes plantas rite cognitas ad genera relatas, cum diferentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas

Biodiversity Heritage Library, Holding Ins: 1908 facsimile from NYSU, tomus 1: tomus 2:

Nesom, Guy.  Flora of North America

Greene, Edward Lee, 1897  Pittonia :a series of papers relating to botany and botanists, pg 245. Holding Institution:  Missouri Botanical Garden

Fernald, M. L. “A NORTHERN VARIETY OF ASTER LINARIIFOLIUS.” Rhodora, vol. 16, no. 191, 1914, pp. 192–94. JSTOR, Accessed 25 June 2023.

Burgess, E. S., 1906.  ‘Species and Variations of Biotin Asters with Discussion of Variability in Aster’, Mem. Torr. Bot. Club.  Stable URL:

Etymology from Flora of North America


Ionactis linariifolia (Linnaeus) Greene, Pittonia. 3: 245. 1897. Flax-leaf ankle-aster, flaxleaf whitetop or aster, aster à feuilles de linaires Aster linariifolius Linnaeus, Sp. Pl. 2: 874. 1753; which cites Hortus cliff 408, Gronovius 99, Ray lugdib 167, Morison Hist 121. A. linariifolius var. victorinii Fernald


Greene’s Genera…..

In the Kew, POWO database, E. L. Greene is credited with 127 genera, most of which are de novo, 43 of which are currently “Accepted”, with the remainder considered synonyms.  Greene’s most ardent interest revolved around a few families, though he would dip into other groups that intrigued him.  Below is a simple summary, by family, of generic names he proposed (at least those I could discover in POWO), with an indication as to how many have been accepted versus those in the catacombs of synonymy:

Amaranthaceae – 1 in synonymy

Anacardiaceae – 1 in synonmy

Apiaceae – 1 ACCEPTED

Aslcepiadaceae – 3 in synonymy

Asteraceae – 18 ACCEPTED, 23 synonymy

Boraginaceae – 2 ACCEPTED, 2 synonymy

Brassicaceae – 7 ACCEPTED, 16 synonymy

Campanulaceae – 1 în synonymy

Caryophyllaceae – 1 in synonymy

Cleomaceae – 4 in synonymy

Crossosomataceae – 1 in synonymy

Cucurbitaceae – 1 ACCEPTED

Fabaceae – 3 in synonymy

Lamiaceae – 2 in synonymy

Malvaceae – 3 ACCEPTED, 2 in synonymy

Orchidaceae – 1 in synonymy

Orobanchaceae – 1 in synonymy

Polemoniaceae – 1 ACCEPTED

Papaveraceae – 2 in synonymy

Phrymaceae – 1 ACCEPTED

Polemoniaceae – 3 ACCEPTED, 1 in synonymy

Polygonaceae – 1 ACCEPTED, 1 in synonymy

Pteridaceae – 1 in synonymy

Ranunculaceae – 2 ACCEPTED, 1 in synonymy

Rosaceae – 13 in synonymy (8 related to Rubus)

Rutaceae – 1 in synonymy

Sarraceniaceae – 1 in synonym

Schlizaeceae – 1 in synonymy

Styracaceae – 1 in synonymy

Taxaceae – 1 in synonymy

Vitaceae – 1 in synonymy

Zygophyllaceae – 1 ACCEPTED

Some generalizations I draw from this are that:

  • Greene dedicated his greatest attention to a few families, most significantly the Asteraceae, but also the Brassicaceae (& the allied Cleomaceae), Malvaceae, Polemoniaceae, Polygonaceae, Ranunculaceae, and Rosaceae. 
  • Outside the Asteraceae, some genera drew particular attention – 1. Streptanthus (Brassicaceae), for which he proposed 9 genera relegated to synonymy, 2. Cleome (Cleomaceae), for which he proposed 4 genera relegated to synonymy, and 3. Rubus (Rosaceae), for which he proposed 8 genera currently in the synonymy dustbins.
  • Taxonomists working in some families, particularly the Asteraceae, Brassicaceae (with exception of Streptanthus), Malvaceae, and Polemoniaceae, have proven more sympathetic to Greene’s opinions.  

Thus, back to giving Jepson the final words:

“On this occasion I did so (he wrote it out perfectly) and there is now preserved a picture of Greene’s personality, judicial and unprejudiced, and divested of immaterial matters. It is my hope that it will help preserve the memory of a man who was every inch an individual.

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