One Plant Divided
The Story of ‘Bishop of Llandaff’
“In some Native languages the term for plants translates to ‘those who take care of us.”
Robin Wall Kimmerer
In 1924, a modest nursery in Cardiff, Wales released a dahlia with black-bronze leaves and a single row of vermilion petals so vivid they looked painted. Its name, ‘Bishop of Llandaff’, came not from a marketing department but from a man in a clerical collar. The story goes that Joshua Pritchard Hughes, then Bishop of Llandaff and known for his earnest, evangelical bent, visited the nursery of Fred Treseder and selected the plant himself. Whether the bishop was a gardener, a flower lover, or simply obliging a local grower is unclear. What is certain is that the plant was named for him, and the name stuck. A century later, it still holds.
Post-war Cardiff in 1924 was a city caught between worlds. The docks that had once shipped more coal than any port on Earth were already slowing, yet coal dust still clung to window sills. Men recently home from the trenches were trading stiff Edwardian collars for softer sports jackets, and Britain’s first Labour government had taken office that January. Even so, class lines remained firm. Shipping magnates and landed families commissioned formal terraces and hired professional gardeners, while dockworkers and miners filled allotments with winter-hardy standbys like leeks and root crops alongside seasonal borders of pot marigolds, sweet peas, and dahlias.
Pwll Coch Nurseries sat somewhere between those worlds. Founded in the 1870s by Stephen Treseder and run in 1924 by his grandson Fred, the nursery supplied everything from bedding pansies for small front yards to specimen lilies for the Cory family’s estate at Dyffryn. That mix of customers gave Fred a sharp eye. He knew a plant had to be both eye-catching and forgiving if it was to travel beyond a single estate wall.
Local lore suggests that during one of Fred’s routine walk-throughs of the propagation frames, Bishop Hughes paused at a seedling unlike the others. The foliage was almost black, the flower a disciplined compass of red petals around a dark center: simple, striking, modern. Hughes gave his blessing, and Treseder entered the name ‘Bishop of Llandaff’ in his ledger.
Bishops in Wales still carried real civic weight, and Hughes was known for turning up in person wherever church ground met public life. He oversaw the gardens around Llandaff Palace - modest beds, but visible from the cathedral green - so every spring he ordered fresh stock from local nurseries. Treseder’s was the largest within an easy car ride, supplying roses to Cardiff Castle one week and hardy perennials to chapel graveyards the next. Hughes had also judged the Cardiff autumn flower show more than once, so a courtesy visit to see the new season’s seedlings would have been both pastoral and practical. Nursery trade papers list his name among local patrons, and a brief note in the South Wales Echo from April 1924 mentions “His Lordship touring Pwll Coch frames with the proprietor.” Spotting a scarlet seedling that matched a liturgical stole was, in all likelihood, serendipity.
The plant traveled quickly. By 1928, it had earned the Royal Horticultural Society’s newly minted Award of Garden Merit. More importantly, it fit the mood of a country ready for gardens that were dramatic but less fussy. It grew to a tidy three feet, bloomed early, and overwintered well. Municipal parks planted it by the hundreds. Cottage gardeners tucked tubers into their potagers beside potatoes. In estate borders, the dark leaves framed pale roses.
Wales offered conditions quite unlike those of London - or of the Royal Botanic Gardens, Kew, on London’s southwestern edge. Mild Atlantic air let tender plants like gunneras survive outdoors, and the city’s coal left a soot-dark film on lintels and laundry, almost poetically reflected in the dark stems and leaves of Bishop.
Horticultural knowledge moved by chapel meetings, miners’ institute lectures, and county exhibitions more than by the scholarly journals that shaped London tastes. A plant had to thrive in that mixed, practical environment to last, and Bishop did.
This was no dinner-plate dahlia, no lavish puff of petals. What Treseder bred - likely from species hybrids involving Dahlia pinnata and D. coccinea - was something different: an upright plant, rarely over a meter tall, with finely divided, deeply pigmented foliage and tidy, open flowers that revealed their dark central disc to bees. The contrast was striking, the form disciplined, the color enough to stop you mid-step.
Some of its descendants were deliberate: ‘Bishop of Oxford’, ‘Bishop of Canterbury’, ‘Bishop’s Children’, a seed strain that mimicked the dark foliage and broadened the color palette. Others came from gardeners letting it self-seed, or passing tubers to friends. What’s remarkable is how often the original seems to hold its shape.
And that shape - red petals, dark disc, black-bronze leaves - is where the real mystery begins.
What happens when a single plant is divided across continents and decades? Is it still the same plant? How much changes when tubers are multiplied by hand, year after year, by thousands of different growers? What happens to a name, to a lineage, when it becomes shorthand for a look, a feeling, or a color rather than a fixed genetic identity?
You would think it would stay the same. A named dahlia variety, propagated vegetatively, should remain genetically stable. And in the case of ‘Bishop of Llandaff’, firsthand observation often supports that. The foliage remains dark and finely cut. The bloom stays disciplined - vermillion petals, open center, clean lines. Gardeners across decades describe the same basic silhouette. There is something remarkably consistent about the plant itself.
And yet, how it’s described, how it’s classified wavers.
Some call it single, others semi-double. Some list it as peony-form. Foliage descriptions range from green to bronze to near-black. Even its height fluctuates from 3 to 5 feet depending on the catalog. These may seem like minor discrepancies, but in the dahlia world - where classification drives sales, showing, and breeding - they matter.
Stack a few old descriptions together and the problem reveals itself. Not in the plant, but in our perception of it.
From the 1953 Swan Island Dahlias catalog:
“4–5 feet. Cut-leaf, burgundy-bronze foliage with glowing scarlet, almost-single blooms. A favorite for mass planting.”
A practical, grower-focused description - concerned with height, reliability, and foliage, with a nod to the flower form as “almost-single.”
From Old House Gardens (c. 2000):
“With cut-leaf, burgundy-bronze foliage and glowing scarlet, almost-single flowers sparked by a ring of vivid yellow stamens. Type: peony/semi-double.”
Here, the same bloom is classed as “peony/semi-double,” nudged into a different category entirely, perhaps because that’s where the catalog needed it to go, or because definitions had softened.
From the RHS Dahlia Register:
“Semi-double, 3 to 4 inches. Scarlet with dark central disc. Foliage: dark bronze. Form: peony.”
Even the official registry blurs the line, blending terms that are meant to be distinct.
So which is it?
Perhaps all of them, and none of them. The plant has not shifted, but our attempts to describe it have. What we’re seeing here is not botanical drift, but linguistic drift. Classification stretches, vocabulary bends, and marketing adapts. The plant remains genetically consistent, at least in appearance, but the frame we put around it flickers.
This is not a failure of botany, but a window into how much of gardening is subjective. The descriptions change not because the plant has, but because humans have - our systems, our tastes, our catalog deadlines. It reveals the limits not of the flower, but of our ability to categorize it neatly.
Yet despite the shifting labels, it’s still unmistakably ‘Bishop of Llandaff’. The picture clears when we trade fashion for fact: the plant stays the same all the way down to its cells, while the words around it drift a little. Each time a catalog renames the clone, nothing in the dahlia changes, only the trend pages. At that point the name ‘Bishop of Llandaff’ turns into simple shorthand, passed from one gardener to the next on plant tags, seed swaps, and order forms. Like a folk song, it changes by a hair with every hand that passes it on.
While other dahlias were caught up in naming wars, in scarcity pricing, in the booming hype of seasonal releases, 'Bishop of Llandaff' kept its head down. It never had to be fashionable. It just had to keep going.
And keep going it did. In the noisy world of gardening trends, it stood apart. Not with flash, but with certainty. You didn’t necessarily plant Bishop to impress anyone. You planted it because it felt familiar. It had roots in places we didn’t even know we remembered - churchyards, municipal beds, the garden at the edge of childhood.
What does it mean to be one plant - divided, carried, and grown in thousands of gardens?
Some of the largest living organisms on Earth don’t appear unified at all. The aspen grove in Utah, known as Pando, spans over 100 acres. Each “tree” is a shoot from a single root system. Genetically, they are one being. A honey fungus in Oregon, too, stretches across miles underground, appearing as many while remaining a single organism.
In horticulture, we’ve borrowed this strategy. We clone. We divide. We take a cutting from one plant and grow it somewhere else - same DNA, new place. It’s a kind of biological sleight of hand. And few plants have achieved that trick more elegantly than 'Bishop of Llandaff'.
This red-flowered, dark-leaved dahlia has been passed from hand to hand for more than a century. Most plants called ‘Bishop of Llandaff’ today are likely the exact same genome as the seedling tagged in Cardiff in the 1920s. In a strict biological sense they’re not descendants, they’re extensions. Same cells, same code. Not replicas, not replacements - just one organism divided and spread.
That alone is remarkable, yet the real genius of Bishop lies in what happens next.
Its open center invites bees, so every clone not only blooms but sets seed by the handful. Each seed pod reshuffles the deck, opening the door to variation. Gardeners have been sowing those seeds for decades. From one tray came a fully double orange bloom that retained the dark, almost-black foliage, a chance seedling of ‘Bishop of Llandaff’ selected and introduced by nurseryman David Howard of Howard Nurseries in the late 1950s. Proof that a single Bishop can produce remarkable offspring.
Bishop, then, lives in two worlds at once. It keeps its shape when you divide its tubers, and it begins again when you sow its seed. That’s a masterstroke of survival. In evolutionary terms, it’s about as efficient as a plant can be: continuity by clone, variation by seed. Most organisms don’t get to play both sides. Dahlias do.
Passed on by tuber, by cutting, by saved seed, it continues by division and begins again by seed. One red dahlia, shared from local parishes to distant continents.