We’ve run into Henri Cassini before, in a post on Eurybia that included a bit of his background. And we will run into him again, he’s a big deal in the history of “Synantherology”. But as important as Cassini is in the taxonomic doyens of the Asters, he doesn’t fly solo. A lot of botanical effort has been necessary to unravel and undergird the taxa he created. Today, a researcher would take great care to indicate type specimens for any new species, as well as designate the type species on which a genus is founded. But that wasn’t protocol in the first half of the 19th century, when Cassini studied and wrote about Composites. In fact, his writings remain unclear, even today, as to whether he considered many of his taxa to be full-fledged genera, or sub-genera. Since a lack of protocol and clarity did not hinder Henri Cassini, it’s excellent we have guides. In 2010, Christian Flann, Werner Greeter, and D. J. Nicholas published a remarkably helpful Assessment of his work, in which we learn Cassini had described over 391 genera, “130 of which are accepted today, around 8% of the accepted generic names in the family”. His hands are all over the constellations of Asteraceae.
Were it not for the 2010 Assessment, understanding how the generic name Emilia has been applied to over 120 species, the group would have been difficult to understand. A plant Willdenow had named Cacalia sagittata (in 1803) struck Cassini as needing its own genus (or subgenus, as the case may be), which he resolved in 1817 in publishing Emilia. Due to technical issues, that taxon now bears the name Emilia coccinea, serving as the type species for the genus – an issue resolved by later researchers.
Cassini’s treatment is brief. Searching for facts, such as the reason he selected this name, requires some guesswork. In his Flora of North America treatment, Theodore Barkley suggests the name honored a person, perhaps an Emile, or an Emilie. Investigating the name Emilia, I find a reason more to my own liking, which would require Cassini’s confusing the name with Greek root words that relate to “blood” – thus alluding to the flower color. Or, there’s always Emilia, who ran afoul of Cassio in Shakespeare’s ‘Othello’. But Cassini was French.
The Main Story
Leaving Cassini behind, the plants I’ve encountered in our region fit the description of Emilia fosbergii, a lovely, ephemeral escapee you may encounter anywhere in Florida, perhaps anywhere in the world. There are issues, however. The Florida ISB reports three species of Emilia present, while Flora North America only accepts two in the flora of the continent. Though my plants seem to be E. fosbergii, and not the alternative, Emilia sonchifolius, it isn’t the easiest choice, relying fully on aspects of flowers that may be hard to detect and the leaves, which can be highly variable.
Accepting this is Emilia fosbergii, a native to Africa that has achieved worldwide distribution, presents a mystery. How can a plant, named as recently as 1975, by an American botanist based on a specimen from Nassau…, how could that plant have escaped notice over several centuries of descriptive botany? Why isn’t our plant, the very tender but quickly germinating and maturing “weed” we’ve adopted as the “Florida Tasselflower”, simply, the same as the type for the genus, Emilia coccinea? Those questions were, indeed, addressed by a most wonderful botanist, the fellow who authored this newer epithet, Dan Nicholson, in his 1975 paper ‘Emilia fosbergii, A New Species (Phytologia, 32:33-34).
Nicholson rejects my concern that plants we find in nursery stock and tended-gardens could be Emilia coccinea, or even the competing Emilia sonchifolia. He reports: “All neotropical specimens of Emilia studied by the author were referable to three species. One species, E. coccinea from eastern Africa, is only rarely collected as an escape from gardens at relatively high elevations (1000-2000m) or latitudes. This species has orangish-red flowers which are only half enclosed by the involucre, entire or partially shallowly dentate leaf margins, and elongate coralla lobes 1.y-2.1 mm long.
The second species, E. sonchifolia, from South Asia, is commonly collected in lowlands (0-1000 m). This species has light purple flowers which are completely enclosed in the involucre, strongly lyrate lower leaves, and short corolla lobes 0.5-0.7 m long.
The third and most frequently collected species, here first recognized as distinct from all previously described species, is commonly collected at middle elevations, 100=1500 m. This species has red flowers which are three-quarters enclosed by the involucre, coarsely dentate leaves, and corolla lobes 1.2-1.4 mm long…
The present author stepped into this quagmire in early 1974 while innocently identifying a drawing of an Emilia sent by Mr. Penny Honeychurch of Roseau, Dominica. Dr. F. Raymond Fosberg was able to show me, a non-astrologist, how to identify neo-tropicdal specimens of Emilia in three minutes. I was astonished to find that no one had clearly elucidated these three taxa….
This led to his choice of names for the new species:
How did I encounter this plant? We were parked in a shopping center in Panama City, one in which the planting islands are well-maintained. In fact, they had been spruced up recently with addition of mulch. Growing from the mulch, in a few locations, were charming plants I knew right off had to be considered weeds. I copped a small sample, roots and all, knowing it begged weeding, and brought it home in a cup of stale Diet Coke. Tucked into a moist planter, the frail plant thrived. Now, progeny show up, just one or two at at a time. It’s friendly, as weeds go, and it churns out those ruby red flowers.
I was able to identify my purloined treasure to genus using PictureThis, a smartphone app. Later, with the Wunderlin & Hansen key and images on the ISB Plant Atlas, I confirmed, with reservations, the identity as Emilia fosbergii. I say “with reservation” because a key dichotomy, “style arms tapered” vs. “style arms truncate,” isn’t very diagnostic using a handlens.
How might you identify it? Well, in habit it looks like a pink-flowered Lactuca or Krigia, which is awkward and misleading, since Emelia, with all disc flowers, is in the Senecio Subtribe, tucked into the Aster Tribe, far different from Lactuca and Krigia, which have similar-appearing heads, but with all ligulate flowers. If you’ve ever dealt with the non-native Ragwort (Senecio brasiliensis) or the Common Groundsel (Senecio vulgaris), those flower heads are similarly constructed. Or perhaps you’ve grown String of Pearls, Curio (Senecio) rowleyanus, and had surprise when it flowered as a discoid daisy.
If you encounter a modest, very soft herb with small tufted flower heads in ruby read, then check for sparse branching and a few clasping cauline leaves that quickly reduce from base to branching . If those characters are apparent, the plant is likely Emilia. For confirmation, check the disk flowers. If they extend 2-4 mm beyond the green involucre, you’re pretty solid with Emilia fosbergii.
I probably should not be offering advice on cultivation. It’s likely you’ll encounter Emilia as a contaminant in nursery plants. if it shows up in a moist flower bed or some larger pots with nice hummus-y soil, just don’t weed it out aggressively. It’s a camp follower.
Photographs of the entire plant shown above were made on 27 June. A month later, on 26 July I took additional photographs of the plant (now a pet, I guess.) Here is one of those. Below that photo, I’ve paired the two images, 27 June and 26 July.
Had I planned this, the comparison would be more obvious, and there’d have been a scale. What you see is the way this plant continues to rebuild itself, an on-going process of rejuvenation. The two young growths in the photo on the left are the mature flowering stems in the right-hand photograph.
In the beginning, a single scape rose from the base. As that developed, buds from lower leaves began to elongate. In succession, each node sent out a new flowering stem with its own 2-3 nodes, each harboring buds that might develop. Botanists use the term “iteration” for a growth sequence that continues like this. The entire plant seems to be a slow-growing inflorescence, creating new iterative branches, with no hint (to date) as to termination. My assumption is that successive branches either will generate fewer nodes, or at some point the axillary branches will cease to elongate. I’ll be curious to see if shorter days impact the generation of new flowering stems.
Barkley, Theodore, Emilia, Flora of North America.
Cassini, Henri, 1817. ‘Aperçu des Genres nouveaus, formépar M. Hernri Cassini, dans la famille des Synanthérées. Quatriême Fascicule’, Bull. Sci. Soc. Philom. Paris 1817: 68 https://www.biodiversitylibrary.org/page/4439627
Nicholson, Dan H., 1975. ‘Emilia fosbergii, A New Species’, Phytologia 32: 34 https://www.biodiversitylibrary.org/page/12971250
Wight, Robert. 1834, Contr. Bot. India: 24. Source: Wellcome Library Wight, Robert, 1796-1872. no 89016332 https://archive.org/details/b29297023/page/n2/mode/1up
Flann, Christain, Werner Greuter, & D.J. Nicholas Hind, 2010. Cassini’s Compositae genera: A nomenclatural and taxonomic assessment. Taxon 59(4) 1206-1244 https://www.jstor.org/stable/20773991