Named for: Joseph Clemens (1862 to 1936) and Mary Strong Clemens (1873 to 1968), plant collectors
Published in: Fraterna 14(3): 12 (2001), by Ted Green
Type specimen: Originally Green, T. 91032 (holotype, Bishop Museum, Honolulu, now missing); formally replaced in 2017 by Clemens, J. & M.S. 26358, collected 8 September 1931, Mount Kinabalu, Sabah (neotype at Kew, isoneotypes at BM, BO, L)
Status today: Accepted, per IPNI and Kew's Plants of the World Online (2026)
The physical proof this plant's name legally rests on today is not the specimen it was first published with.
In 2001, when Ted Green named this hoya, he pointed to a specimen of his own: material he had collected near Poring, Sabah, in 1991, grown on in his Hawaii greenhouses, and pressed at some later point. That specimen was filed at Honolulu's Bishop Museum. Sometime before 2017, it went missing from the museum that held it, not destroyed as far as anyone can tell, just gone, the way things go missing in large herbaria over enough decades.
In 2017, botanist Michele Rodda, untangling this mess, did not reach for whatever specimen happened to be convenient. He went back through the records and designated as the new type an actual specimen collected by the two people this plant is named for, gathered on Mount Kinabalu on 8 September 1931, seventy years before the plant even carried this name, and eighty six years before anyone would need it to repair a broken record.
I want to spend this post telling you about the two people that anchor now belongs to, because it might be the best story I have come across since I started this series.
Start with the name itself, because even the name carries a small unresolved question.
The species was published in 2001 in Fraterna, the newsletter of the International Hoya Association, by Ted Green, the same nurseryman whose name has come up before on this blog. Green named the plant for a husband and wife together, and the ending of the word tells you that: clemensiorum, the plural form used when honoring more than one person, rather than clemensii, which would honor just one.
It was not published that way the first time. I tracked down the actual original 2001 issue of Fraterna, and Green's first description names the plant Hoya clemensii, honoring one Clemens, not two. His etymology note in that same issue reads: "This handsome leafed Hoya is named after J. and M. S. Clemens, who spent much time botanizing on Mt. Kinabalu and other places in Sabah, Malaysia." He clearly meant to honor them both. The grammar did not.
Someone caught it. A few issues later, in the same volume, Green published a correction, and I want to give you his own words for it: "It has been brought to my attention that my naming the handsome Borneo species Hoya clemensii is in error. The plant is correct, it is just that the name does not follow article 60, note 3 Ex. 25 of the International Code of Botanical Nomenclature. Since I named it after the two Clemenses, it must be Hoya clemensiorum." He cited the actual rule of botanical Latin he had broken, fixed it in print, and moved on. That correction never made it into IPNI or Kew's own database, which show only clemensiorum with no history attached. But it happened, in the pages of the newsletter that started it all.
Joseph Clemens was born in December 1862 in Cornwall, in the far southwest of England, the son of a Cornish iron miner named Charles Clemens. Around age five, the family emigrated to Pennsylvania. He was, by his own family's account, the only one of five brothers who did not go into the mines.
He became a Methodist minister, then in 1901 a chaplain in the United States Army, a post that took him to Hawaii with the 15th Infantry, then to the Philippines, first Samar and later Mindanao, then through the First World War in France. He retired from the Army in 1918.
Before I go any further with Joseph, I want to stop and give Mary her own introduction, because the record itself never quite does. Joseph's early life comes with a hometown, a father, a trade, a family story. Mary's does not, not to anywhere near the same degree. What survives is plain and short. She was born Mary Strong on 3 January 1873, somewhere in Sullivan County, New York, and whatever happened in the two decades of her life before she met Joseph has not surfaced anywhere I have been able to find. I am not going to paper over that gap with a guess. It is part of what this story actually is, a record that kept careful track of one of them and barely noticed the other, right from the start.
It was there, somewhere in those same years, that Joseph met her, at the Williamsport Seminary in Pennsylvania. For a while, the exact date of their marriage was the one thing about this story I could not pin down. Not anymore. Dickinson College's Archives and Special Collections, Joseph's alma mater, went back into the record for me, and the record turned out to be specific. Joseph and Mary were married at noon on Wednesday, 8 January 1896, in Williamsport, five days after Mary's own twenty third birthday, a detail Joseph's diary gives away almost by accident by recording both events in the same week. Two groomsmen and two maids stood up with them and four ushers pulled from Joseph's own fraternity at Dickinson. Thirty three guests sat down to dinner afterward, and by four that afternoon the new husband and wife were on a train to Harrisburg. Joseph wrote every bit of it down himself that same night, in the diary Dickinson's archives still hold, transcribed in 1997 by Nelda B. Ikenberry. The Harrisburg Telegraph confirmed it the next day, tucked into the Cumberland Valley column: "Rev. Joseph Clemens, of Mont Alto, wedded Miss Mary Knapp Strong, of Williamsport, yesterday." It is also where I found Mary's actual middle name, Knapp, which does not appear anywhere else in the record I have seen. The same archives settled a smaller question while they were at it. Dickinson's own matriculation register shows Joseph entering as a freshman in November 1890, at age twenty seven, and it lists no middle name for him anywhere in the college's records. As far as the paperwork goes, he did not have one.
Once you list the places, it stops sounding like a series of trips and starts sounding like a life spent almost entirely elsewhere. California, Utah, Oklahoma, and Texas in the early years. The Philippines for most of a decade. China, in the provinces then called Chihli and Shantung. French Indochina. British North Borneo, where in a single six week stretch in 1915, Mary is credited with finding roughly a hundred species new to science. Sarawak, for a six month expedition in 1929. Java. Singapore.
By the time they reached Borneo again in the 1930s, the roles between them had reversed from what anyone of that era would have expected. Mary collected. Joseph, the former army chaplain, dried, pressed, and packed the specimens for shipment. She is credited with over twenty thousand specimens by 1930 alone, distributed to herbaria in Berlin, Michigan, Tokyo, and eventually New York and Queensland.
It is also fair to say that botanists grew wary, over time, of Mary's own species identifications on her labels, even as her raw material was prized without question. That distinction matters in botany, and I think it says something true about her. She was fearless about finding the plant. She was not always right about what she had found. That does not diminish her. It makes her a real person rather than a legend.
They had no children. I mention it because it changes how you read everything that follows. Whatever devotion two people can put into forty years of marriage seems, in this case, to have gone almost entirely into the work, and into each other.
On 16 August 1935, Joseph and Mary arrived at Salamaua, in what was then the Mandated Territory of New Guinea, to begin collecting on the Huon Peninsula. Joseph was seventy two when they arrived. On 21 January 1936, he died on the Wareo cart road, north of Sattelberg, on his way to a German Lutheran Mission conference in Finschhafen. The cause was food poisoning, from spoiled wild boar meat. Not a war wound, not the jungle in any dramatic sense. Spoiled meat, on a remote stretch of road, at the end of a long life.
Mary recorded his death herself, in her own hand, on the label of a specimen she collected not long after: Clemens 1668, a nutmeg relative now known as Myristica lancifolia var. clemensii, held today in Berlin. The label reads, "It was under this tree that my soul companion for over 40 years of wedded life, bade me farewell for the higher life." A scientific record, carrying a sentence that has nothing to do with botany at all.
Mary did not leave. She stayed in New Guinea and kept collecting alone for another five and a half years, until the Japanese invasion forced her evacuation to Australia at the end of December 1941. In that final stretch by herself, she is credited with roughly fourteen thousand additional specimens.
That label is the only place I have found her own words about losing him. It is not a diary entry or a letter, just one sentence folded into a plant record that no one but her was ever likely to read closely. I think it says as much as a fuller account could. She kept working there, alone, for longer than most collectors work in a full career with a partner.
Mary settled in Queensland after the evacuation, working out of the state herbarium in Brisbane, and kept collecting into her seventies: Charleville in 1945, the Jericho district in 1946, Mackay in 1947, Maryborough in 1948, Ingham and Tully in 1949. A broken hip in 1950 ended her long field trips, though she kept working from a desk for years after.
She died on 13 April 1968, in Chermside, Brisbane, at ninety five. By then she had spent very nearly half a century collecting plants across four continents, more than thirty years of it as half of a working partnership, and the last thirty two years of it alone.
Other botanists named other species for the couple across other genera over the decades, a common mark of collectors at their scale. This hoya is one tribute among several, not the only one.
Today, Hoya clemensiorum stands exactly as Rodda left it in 2017: accepted, its own species, unquestioned by anyone with the standing to make the question stick. Somewhere among the hundreds of hoyas that carry a person's name, this is one of the few that carries two.
What gets me about this one is how much of it is still standing without needing anything I couldn't check myself. A name Ted Green got wrong in print, in a way that only honored one of them, and then corrected himself, in the same publication, rather than let it quietly stay wrong. A type specimen that went missing and got replaced not with whatever was convenient, but with the collectors' own work, sitting there waiting the whole time. A woman who wrote her husband's death into a plant label instead of a private page, and then collected for thirty two more years without him.
None of that needed a discovered sentence to be worth telling. It is not as tidy as one would have been. It is what is actually true, and I think that is enough.
So if you know anything more about Joseph or Mary Strong Clemens, or their collecting years, let me know.
I will add it to the permanent record, and I will put your name on it.
Names have roots too. Worth knowing whose.
Roots First. Always.
Phil
Sources & References:
Green, T. (2001). Hoya clemensiorum T.Green. Fraterna, 14(3): 12.
Rodda, M. (2017). Index of names and types of Hoya (Apocynaceae: Asclepiadoideae) of Borneo. Gardens' Bulletin Singapore, 69(1): 33 to 65.
International Plant Names Index (IPNI): urn:lsid:ipni.org:names:20005847-1
Royal Botanic Gardens, Kew: Plants of the World Online (POWO)
Dickinson College Archives & Special Collections, "Joseph Clemens (1862 to 1936)"
Dickinson College Archives & Special Collections, "Joseph Clemens diaries" (MC 2001.17): 1895 and 1896 diary transcripts, transcribed by Nelda B. Ikenberry, 1997
Dickinson College Archives & Special Collections, matriculation register, Class of 1894
Harrisburg Telegraph, "Cumberland Valley" news, 9 January 1896
Wikipedia, "Joseph Clemens" and "Mary Strong Clemens"
New York Botanical Garden, Finding Guide to the Mary Strong Clemens Papers
Australian National Herbarium biography of Mary Strong Clemens
Global Biodiversity Information Facility (GBIF): occurrence record for Clemens, J. & M.S. 26358, 8 September 1931, Mount Kinabalu
Fraterna, vol. 14, 2001 (bound annual volume), International Hoya Association, digitized by the New York Botanical Garden via the Biodiversity Heritage Library: original description and etymology, and Green's later correction notice within the same volume.
Leaflets of Western Botany, vol. VIII, no. 5, p. 88: biographical note on Mary Strong Clemens, giving her birthplace as Cochecton Center, N.Y.
Conn, B.J. (1990). "Mary Strong Clemens: a botanical collector in New Guinea (1935 to 1941)." In P.S. Short (ed.), History of Systematic Botany in Australasia: Proceedings of a Symposium Held at the University of Melbourne, 25 to 27 May 1988. Melbourne: Australian Systematic Botany Society, p. 217. Source of the account of Joseph's death on the Wareo cart road and of Mary's specimen-label inscription, quoting Sinclair (1968).
Sinclair, J. (1968). "Florae Malesianae Precursores XLII: The genus Myristica in south and southeast Asia." Gardens' Bulletin Singapore, 23: 1 to 540 (p. 465): original publication of the label text on Clemens 1668, confirmed directly against a scan of the printed page, which also gives the specimen's exact location, "Wareo cart road," and Joseph's cause of death, "food-poisoning," in Sinclair's own words.