A Quick Look at the Rose Subgenera

Roses are native to locales all across the Northern Hemisphere, and there's a lot of genetic diversity within the genus (little of which is found in the mainstream cultivars, however). Taxonomists have placed the vast majority of rose species within subgenus Rosa, which is further divided into many sections. These are the species one typically thinks about when roses are considered.

Rosa glutinosa, in subgenus Rosa, section Caninae. Like R. eglanteria (also in Caninae), this species has glandular leaves and buds which exude pine-to-green-apple-scented oils.

Rosa carolina, type of section Carolinae within subgenus Rosa. Although the flowers are typically medium pink, this one was bleached to white in the sun (a tinge of pink still remains).

Next we get into the relatively weird subgenera, which could be considered to be on the genetic fringes of the genus: Hulthemia, Hesperhodos, and Platyrhodon. Their separate status is confirmed by their general unwillingness to breed readily with members of other sections, as well as very distinct morphological characteristics.

Rosa persica, the sole member of subgenus Hulthemia, was once placed in its own genus under the moniker Hulthemia persica. It is native to the Middle East, where it grows as suckering briar. The species itself is notoriously difficult to cultivate, and the close hybrids are also known to be finicky.

This one is really fascinating-- it's sort of a rose, but there are remarkable differences, especially the simple rather than compound leaves. (Photo credit)

Breeders have been working to incorporate the red eye into mainstream garden cultivars-- notably James Sproul (here's his excellent blog). Even in F1 hybrids, the offspring retain the compound leaves of the other subgenera, and so far the red eye has been the only hulthemia-derived characteristic of note.

Hesperhodos carries on the desert briar theme somewhat, as the two Hesperhodos species-- R. stellata and R. minutifolia-- are native to southern California and Mexico. These species have been given almost no breeding attention-- but you can read about some of Kim Rupert's exciting developments with Hesperhodos here and here. R. stellata mirifica is considered to be the most approachable form-- Graham Stuart Thomas reported that it grew well in Surrey; it's currently available from Greenmantle Nursery. Unfortunately I don't think there is a commercial source for minutifolia for US gardeners.

R. stellata (Photo credit)

This slightly sunburnt R. minutifolia barely looks like a rose! The leaves remind me of angel pelargoniums. (Photo credit)

Last is Platyrhodon, perhaps the easiest of these fringe roses to grow. It has long been included in US gardens and is commonly known as "the chestnut rose" for its nutty-looking hips. The most frequently seen form, R. roxburghii, is actually the double variant (given this name since it was the first to be documented by Western botanical explorers). The actual vanilla species, with single flowers, is known as R. roxburghii normalis. These can grow to be very large shrubs, having thick stems with brown, peeling bark.

R. roxburghii (Photo credit)

R. roxburghii hips

Detail of a particularly woody roxburghii stem (Photo credit)

While these species are very interesting in their own right, it is particularly mind boggling to consider that these plants are in the very same genus as the hybrid teas! Perhaps the diversity of Rosa is a large reason why it has so many devoted experts. Since amateur hybridizing seems to be very involved with the species at the moment, I think that as time progresses we will have more access to plants with these "fringe" genetics. 

Recalcitrant Orchids, Indoors!

If you asked random people, especially people who aren't gardeners, what the most persnickety plants are, I'd wager that a prominent response would be "orchids" (I'm sure roses would be pretty high up there too-- but on to orchids for now, as it's summer and tropical-looking things match the current humidity).

I think a lot of this perception stems from those florist phalaenopsis, which are grown en masse under virtually perfect conditions, then rudely transported to a dim, dry, cool spot in someone's home. The flowers from the plant's happier greenhouse days wither away, and the owner is left with wilty-looking leaves dying a slow death on a bed of dry sphagnum moss. What to do with these plants, other than to toss them out and surmise that all orchids must be "hard to grow?"

B. 'Little Stars'

I was sort of in the same boat for nearly three years with an orchid of my own, the Brassavola nodosa hybrid 'Little Stars.' It never bloomed for years, although it did have interesting, healthy-looking leaves (better foliar interest than what phalaenopsis provides). Then, around this past Christmas, it issued an unusual growth from the base of a leaf-- a cluster of flowers.

The poor thing was in the arid air of a home in wintertime, when the humidity level is that of the Sahara. But it obliged me with a charming trio of greenish-white spidery flowers, each smelling like a lily, reminding me each time I walked into the room of those lily-heavy funeral arrangements. The flowers themselves, I suppose, have a little less appeal than the classic "moth orchids," but I have always liked green blooms.

Here is what a well-grown 'Little Stars' looks like. (CC)

'Little Stars' has not bloomed since, and I've yet to discern what exactly coaxed it into flowering last winter.

'Dr. Huey,' the Uninvited Garden Guest

The future of mass-produced rose bushes seems to lie in own-root propagation. But grafting is still quite common, with nurseries like Weeks, Jackson and Perkins, K&M, etc. offering up many of their cultivars on rootstocks. Chief among those rootstocks, especially where the also-common 'Fortuniana' is not hardy, is 'Dr. Huey,' a crimson wichurana rambler. The understock is almost always more resilient and vigorous than the variety grafted on top, so when 'Peace,' a David Austin rose, or what have you succumbs to disease or trauma we are left with an anxious-to-grow 'Dr. Huey.' Some gardeners are perplexed when they find that their lovely rose has been transformed into a rambler, which blooms once in late spring, and then revels in black spot disease for the subsequent months.

As is typical of many dark-colored roses, 'Dr. Huey' is more magenta than crimson when it is grown in some shade.

But what would the rose landscape look like if it were not for Dr. Huey? It's an indelible part of our horticultural heritage, and thankfully, since it is not a species such as R. canina or R. multiflora, it never spreads should it crop up. In fact, it seems rather unwilling to breed at all; several of my plants of 'Dr. Huey' (I didn't have the heart to rip them up) obliged me with only one hip, containing one measly seed.

Of course I would not recommend intentionally planting 'Dr. Huey,' and to be frank your garden space is best given over to more worthy varieties that don't have such difficulty with black spot. But in some cases the good doctor should be allowed to stay put-- I once saw the crimson of 'Dr. Huey' peeking out from a sheet of Lonicera japonica, which was blooming at the same time, making a striking combination.

Sunday Sundries: Mississippi River Basin Model

Buddy Butts Park in Jackson, Mississippi is, in some ways, the very picture of state neglect. You'd be hard-pressed to find an entrance road more riddled with potholes! The entire park is imbued with a worn-out and forgotten aura-- especially the most interesting section, the site of the now-derelict Mississippi River Basin Model Waterways Experiment Station.

Visitors to the overgrown Experimentation Site are greeted by the creepy remnants of the pump house.

Work on the Station began in 1943, with the help of German prisoners of war. The model was used to predict flooding events and analyze levees, locks, etc. It was last used in 1973.

Mounds of wire mesh; the mesh was used to simulate the effect of vegetation along the shore.

Interior of the pump house

The model itself, made from contoured segments of concrete, with ridges functioning as levees.

The model is stunningly large-- the Station covered 200 acres and is by far the largest model of the Mississippi ever constructed.

The Station was once a lovely tourist destination.

It is sad to think that models such as this are made obsolete by computer modeling; the Station is impressive, and tangibly educational in a way that computerized models never can be. 

Now for the plant: Asclepias viridis, or "Antelope-Horn Milkweed," found growing by the pump house.

Although the Station would be a good set for a horror film or a nightmare, it's also a thought-provoking reminder of a time when engineers used slide rules and drafted by hand, and the prediction of natural events involved complex, physical scale models. 

The Nativar War

A landscape architect once told me: "I like native plants. Especially slightly improved varieties, if you want to work on those." I had mentioned my interest in plant breeding, as well as natives in particular, when he articulated his preference for nativars.  The simple portmanteau "nativar" (native + cultivar) has proven divisive, pitting horticulturists against naturalists in recent years.

Just picture the scene: on one hand is a man with a career dedicated to the design of beautiful landscapes. He recognizes the ecological benefit of using native plants in his schemes, but he also wants to ensure that these plants can be aesthetically appreciated-- so he picks established nursery-propagated clones noted for a particular color or form. On the other hand is the proprietor of a native plants nursery. Her motivation is providing native plants for naturalists to use in restoration projects, as well as for anyone seeking to create a native landscape scheme. She grows all of her plants from seed, and won't carry any selected cultivars, since that would limit genetic diversity, and make her offerings less suitable for restoration purposes.

Echinacea purpurea (CC)

These differences aren't irreconcilable-- in fact, there really is no controversy in our hypothetical situation, since each person uses the plants suited to their particular projects. Seed-grown straight species for restoration and landscaping purposes; "nativars" for use in landscaping when the resilience of native species is appreciated, but greater diversity in appearance is desired. Where's the "war?"

E. purpurea 'Evan Saul' or 'Sundown,' a nativar. Photographed by Mike Peel (CC)

Some naturalists make de facto categorical denunciations of all nativars (although I don't want to paint with too broad a brush and make categorical denunciations of my own-- more moderate stances do exist). They make some legitimate points, but I think that a lot of the species-only naturalists' criticisms of nativars don't hold up when well-informed end users of nativars know exactly what they are doing. This is especially the case when we consider that some nativars are complex hybrids with a native species or two somewhere back in the lineage, whereas others are naturally-occuring variants or F1 hybrids, perhaps with unique coloration or double flowers. It's clear that the latter have more ecological function and should not be grouped with the more distantly-native varieties.

Now I'll summarize some of the most common arguments employed against use of nativars, as mentioned in the article "Native, or Not So Much?":

1. "Propagating clones inherently limits genetic diversity. This is bad since it inhibits the species' ability to cope with environmental stresses through evolution. Our selection of 'nativars' constitutes unhealthy artificial selection, and should be avoided." 
• This statement is essentially true, meaning that nativars should never be used as substitutes for unselected, seed-grown species in restoration projects, when this better, more natural alternative is available (even though I find the idea that planting genetically-identical clones has some objectively-measurable effect on species' success suspect). But this has no bearing whatsoever on their use in gardens; an ornamental plant with native genes can be grown and appreciated in the very same way nonnative ornamentals can be. 
2. "Certain forms lack the pollinator compatibility, nutritional value, or distinct wildlife-recognizable appearance of the species, and thus should be avoided." 
• True for restoration, but not applicable for the gardener who knows what he's planting.
3. "Selling seed-grown straight species is 'preservation' and is commendable. Cultivars, however, do not have the same ecological value as straight species; therefore, their preservation is less important." 
• I frequently find this argument implicit in discussions of nativars and native gardening. "Genetic diversity" is the name of the game in the natives trade-- except on many occasions when cultivars aren't recognized as legitimate units of genetic diversity because they have relatively little ecological value. The unfortunate result of this mantra is the removal of many interesting cultivars from native nurseries. Once I was looking for a white-variant of a plant for several years, and found a nursery that was in the process of discontinuing it, on the grounds that their propagation of the white variety was "artificial selection." The worst-case scenario would be a dichotomy of mainstream nurseries selling nonnative ornamentals, and native nurseries with proprietors that have been shamed into selling nothing but seed-grown straight species, with no commercial source for nativars.

Is the "nativar war" just an annoying result of today's environmentalist alarmism, or do nativars actually present an ecological threat? I think it boils down to knowing what you're planting-- recognize that certain nativars have some ecological value, while others are basically just ornamentals. Additionally, always plant the straight species when ecological function is paramount. What some naturalists fear-- legitimately-- is that confused consumers will assume that the prettier nativars are just as good for wildlife as the species, and consequently won't plant the species. But the solution is not a shunning of nativars.

The common orange coloration of Asclepias tuberosa (CC)

A yellow form of A. tuberosa (CC); a yellow form called 'Hello Yellow' is often seen in nurseries.

But as to my personal preference-- I often find that the highly-developed nativars are a bit garish. Graham Stuart Thomas pointed out, "[A] fundamental truth is that mankind is, by nature, greedy and dissatisfied with what nature offers."

"Didrangea"

Intergeneric hybrids always seem to be interesting; just the idea of two plants so genetically distinct that they are classified into separate genera being able, somehow, to unite and form offspring, is fascinating. These hybrids certainly aren't your run-of-the-mill traditional crosses.

Everyone knows and loves hydrangeas; in fact, it's impossible to conceive of any high school biology class being able function without some mention of how soil pH affects hydrangea flower color! I took these plants for granted, and until recently they were mentally filed in that "boring common plants" category. But there's another, less common plant, closely related to hydrangea: Dichroa febrifuga. And when I saw hybrids between this species and mainstream hydrangea hybrids, my perspective changed ever so slightly.

Dichroa febrifuga (CC)

The Otis L. Floyd Nursery Research Center in McMinnville, TN has been working on Hydrangea x Dichroa for some time, and while it might be a while before we have a good selection of "didrangeas" at local nurseries, this an exciting development to follow. The horticultural characteristics Dichroa is expected to impart include "flowers that remain blue in the absence of aluminum," "persistent metallic blue fruit," and, as can be seen in the photo of D. febrifuga itself, perhaps some green sepals in combination with other colors.

Although this appears to be on the very frontier of ornamental breeding at the moment, "didrangeas" have appeared before, apparently originating from a natural liaison. Once called "Dichroa versicolor," the hybrid x Didrangea versicolor was introduced to the West by famous botanical explorer Robert Fortune in 1844 (Jearrard's Herbal).

x Didrangea versicolor (CC)

There's no doubt in my mind that one day, we'll be drowning in a veritable rainbow of didrangeas, and gardens everywhere will feature majestic gobs of "metallic blue fruit." Admittedly, I also need to look elsewhere into the rather large world of ornamental hydrangeas, and stop associating them with flimsy florist plants...

Why Do So Many Modern Cultivars Have Stupid Names?

Once upon a time, in Classical Antiquity and the Middle Ages, the garden rose repertoire consisted of various species, like R. gallica and R. moschata, as well as some hybrids between the species, and some slightly-double forms. They all had generic names: Theophrastus, in his Inquiry Into Plants (~350 B.C. to ~287 B.C.) lists garden roses by their location of origin. For instance, "hundred-petalled" roses are given no other moniker and are listed as being found naturalized on Mount Pangaeus; the "sweetest-scented" roses are those grown in Cyrene. No snappy cultivar names!

This situation started to change as humanity approached the Early Modern period; although initially nurserymen still did not understand the principles of plant genetics, they knew that by gathering seed from good garden cultivars, planted in the vicinity of other good parents, they could obtain new novel varieties. The development of new cultivars was vastly accelerated, and vague descriptive names would no longer do. One of the first examples of this new rose production system involves the Dutch and the centifolia class of roses; the oldest centifolia simply had the name 'Old Cabbage,' while the newer roses 'Alain Blanchard' and 'Anais Segalas,' both introduced by dedicated rose purveyors, were named for a Medieval crossbowman and poet, respectively. Catalogs linked specifically-named varieties to the nurserymen that produced them: the new norm still religiously enforced today.

A lot of those cultivar names were historical; many were literary, and others were poetic descriptions of the plants or some cultural association they brought to mind.

David Austin's deliciously soap-scented 'Cymbeline,' from 1983, bears the name of the Shakespearean king.

'Greenmantle,' bred by Lord Penzance in 1895, is named for a character in Sir Walter Scott's Redgauntlet.

The development of "landscape roses," as a semi-distinct class of shrub roses, began relatively recently, with 'Knock Out' and compatriots, along with shifting gardening tastes and trends to specially denote roses that could perform well with minimal fuss ("Earth Kind," "Easy to Love," "Carefree," etc.). Not all of these have stupid names:

'Pretty Lady,' bred by Len Scrivens ~1991. Definitely not a stupid name, and very fitting for such a lovely cultivar.

But the marketing trend for rose "series" makes for some nomenclatural awkwardness. First we must remember that usually it is not the breeders themselves responsible for this, but rather the result of various nursery firms' marketing teams.

There's the 'Knock Out' series from Star/ Conard Pyle, which began with 'Knock Out' and its close derivatives, but also includes less related varieties. I don't think the names of these roses are "stupid," but to be frank they don't quite have the charm of historical/ literary/ poetic names.

'Rainbow Knock Out'

'Sunny Knock Out'

Now we move from "perhaps not pretty, but reasonable and understandable" territory to the decidedly weird and punny cultivar names.

First up is the exciting group of hybrid hulthemias from James Sproul, which feature the characteristic red eye. I love that this bizarre trait derived from a middle-eastern briar on the very fringe of the genus is available to gardeners in growable cultivars.

'Eyeconic Lemonade.' Hopefully you don't have a tendency to groan or cringe when you see puns like this!

While my fascination with hybrid hulthemias and my awe at Mr. Sproul's accomplishments prevents me from calling the name "Eyeconic" stupid (I'm not sure if Sproul created the name himself; perhaps it was whipped up by the marketers), it's not very charming.

Next is the "Oso Easy" and "Oso Happy" roses marketed by Proven Winners. The roses "Oso Easy Lemon Zest" and "Oso Happy Petit Pink" are very good varieties on the dwarfish side... but the names!

'Oso Happy Petit Pink,' commencing a heavy bloom flush.

Now for the most odious, punny names I've come across-- there is a series called "Look a Likes," featuring three roses that (ostensibly) bear a resemblance to other garden plants: 'Look a Likes Phloxy Baby,' 'Look a Likes Hydrangealicious,' and 'Look a Likes BougainFeelYa.' Unfortunately I haven't grown any of these, but I think the ridiculous-- and, dare I say it-- stupid names would make the roses a good conversation piece!

There are quite a few other rose series with similar naming schemes, but this sample, I think, is adequately representative. Similar names are also quite common in other genera used for landscaping.

But I am a bit skeptical of marketers' logic in their choice of "stupid" names. We get it, your company sells roses in a "series," and you stick a prefix in front of each name. However, I don't see how naming roses in this way actually encourages people to purchase them; I'd much rather have roses with interesting, independent names, instead of a moniker that has an industrial- and institutional-sounding prefix attached. The use of series names also implies homogeneity among the included cultivars, and in many cases the roses are not related but rather just have a semi-similar growth habit. I can see how someone expecting 'Sunny Knock Out' to be just like 'Knock Out,' only yellow, could be disappointed.

Landscape roses are a move in the right direction, as long as the older varieties and species are not relegated to oblivion. They are great choices where low-maintenance repeat bloom is desired. But cultivar names are an important part of the enjoyment I derive from plants; I like knowing their history, and the cultural connections associated with the name. Industrial "series" names deprive me of this pleasure, and I look forward to a wholesale return to the independent, older-style names.

Rosa bracteata: A Surprise Sighting

An abandoned road makes a good path for a rustic walk. But the landscape, having been cleared about 15 years ago, was punctuated by young pines, Chinese tallow tree, and various scraggly shrubs and weeds. Initially, the most interesting plant was passionflower (Passiflora incarnata), and I thought that would be the extent of my sightings...

Passionflower: pretty, but ho-hum fare for a weedy trail

A little further on, I caught a glimpse of white in the underbrush.

Tiny white blips near the treeline-- a creeping white-flowered plant.

I was certainly not expecting a rose, as once-blooming roses' blossoms are long gone and are well on their way to having bright fall hips by now.

Although I'd never seen a naturalized one, I was sure at this point that I was looking at the charming Rosa bracteata.

In my view, such flowers are the epitome of purity. The white petals are thick and creamy-looking, somewhat unlike the other common non-native white roses found naturalized in the Southeast: R. wichurana and R. multiflora.

Partially-open blooms

One plant had grown into a sizable bush, laden with large and distinctive hips.

Likely, all of the R. bracteata from this area was the same clone, as it had spread across the ground for some distance, rooting along the way. Here is a shot of a low-lying bracteata thicket.

A bloom peeks out from underneath old woody stems.

I'd not really considered planting any R. bracteata or any of its hybrids before seeing this plant; but now that it's evident that it does well in central Mississippi-- and apparently blooms throughout the summer, satisfying my species rose fix even when the season for that is long gone-- I'll definitely be back to take some cuttings.

The large, wooly hips are a hallmark of bracteata

The hips are quite pubescent, almost looking like little unripe peaches with sepals sticking out of the top! The fuzz looks innocuous, but it can be a skin irritant.

How seedy.

Here is an excerpt from Yuki Mikanagi's Wild Roses of Japan: 

This rose is found only in some of the Yaeyama Islands, which are located in the southern points of Japan, but also is distributed in lowlands of Taiwan and southern areas of China. The author saw it growing wild in grassland on Ishigaki Island. In 1828, a drifting ship reached the coast of Cagayan, northern part of Luzon Island, the Philippines. When the sailors came back to Japan two years later, the captain brought seeds of R. bracteata to Daisuke Baba, a samurai and a famous plant collector. It was the first record of this rose in Japan, and so it came to be called Kakayan-Bara. 

This species has some interesting descendants, including the yellow 'Mermaid' and Ralph Moore's pink 'Muriel.' It definitely has some worthy traits, especially its sporadic rebloom-- but I have read that it is a somewhat recalcitrant breeder.

Although it is not native, it seems unlikely that it is invasive, as I didn't see any evidence that the plant I saw had seeded itself elsewhere. At any rate, it is not on any "noxious weed" lists, so for all practical purposes, I think it can be treated like other ornamental roses and grown where desired.

I'll be getting cuttings, and possibly rooted pieces, of this plant to establish in my own garden later this season; if anyone else wants some, I will be happy to mail out a few plants.