Atlantic Ivy - Overlooked as a Garden Escape?

Atlantic Ivy (Hedera hibernica) is the dominant ivy along the western fringes of Britain, while further east and inland it is generally considered to be replaced by Common Ivy (Hedera helix).  The very robust cultivar 'Hibernica' (also known as 'Irish Ivy') being the exception to this, having been widely planted historically and subsequently has spread widely in suburban areas, railway banks and woodland. Despite this it still seems to be under-recorded. In part this is because in some counties it isn't recorded to cultivar level, instead being lumped under Atlantic Ivy. However, there do seem to be some genuine large gaps that are inconsistent with its ubiquity elsewhere. The BSBI database still lists it and maps it under Common Ivy, which also may confuse matters.

Images of Hedera hibernica 'Hibernica', Swillington Park (VC64)

But this is not the only form grown in gardens, and some cultivars are likely to have been grown for as long as 'Hibernica' and therefore are equally likely to have escaped. I was reminded of this recently, when walking through the woodland on the edge of Oulton Park (VC63). My eye was drawn to what at first glance was a carpet of ivy mixed with abundant tree seedlings, but closer inspection showed these 'seedlings' to be part of a very peculiar and heterophyllous ivy. A few young shoots were gathered to look at under the microscope later, and when I did I found the underside of the youngest leaves (the only reliable place to look, and ignoring the leaf margin and major veins) to have a cover of hairs (trichomes) flat to the leaf surface. So, it was a form of Atlantic Ivy, an identification kindly confirmed later by Hugh McAllister, author of the excellent recent monograph on the genus. Hugh also suggested that it looked like the cultivar 'Gavotte', which in itself is interesting as this cultivar is currently considered to be a form of Common Ivy and therefore would need to be reassigned to Atlantic Ivy.

Hedera hibernica cf. 'Gavotte'

This is the third type of Atlantic Ivy I have found in the woodlands around Oulton Park. 'Hibernica' is of course common throughout, but there is another large leaved form which seems to the old cultivar 'Lobatomajor' (and it may sit within a group of cultivars that comprise the Hibernica Group, as the distinguishing distinctively lobed large leaves only start to appear once it starts to climb).

Hedera hibernica 'Lobatomajor'

So inspired by 'Gavotte', and it being a good autumn project now that most plants have gone over for the year, I visited several woodlands in urban fringe locations this weekend to see if I could find more Atlantic Ivy. Something that turned out to be relatively easy, the trick being to focus on those plants with the largest juvenile foliage and/or leaves redolent of 'Hibernica' in shape. None of these plants was as distinctive as the above forms, and instead resemble more typical wild type Atlantic Ivy. But once you get your eye in they do have a distinctive jizz, and the hairs later confirmed these field identifications. It was by no means dominant within the woodlands concerned, but where it has colonised it generally forms dense stands. I'm recording all these finds as neophytes, as I am assuming that they have a garden or other introduced origin. I suspect focussed searching will find them to be relatively frequent in other suburban and urban edge locations.

Hedera hibernica in Hollinhurst Wood, Allerton Bywater (VC64)

Hedera hibernica in Peasecroft Wood, Great Preston (VC64)

Hedera hibernica near Astley Lane, Swillington to Great Preston (VC64)

Crataegus x rubrinervis

I popped over to Skelton Lake (VC64) today to check up on the bush of Crataegus x rubrinervis (Common Hawthorn C. monogyna x Five-seeded Hawthorn C. pentagyna) I first found in 2018. There are a couple of bushes of Five-seeded Hawthorn a few hundred metres away, and this bush looks like it has arisen in situ.

It has the foliage, large succulent fruit (at their largest they are blackcurrant sized) and suberect sepals (recurving at the tips) of Five-seeded Hawthorn, but with fruit dark red to red-purple rather than purple-black and seeming to ripen later as well. The flesh is reddish coloured, and in this case most of the fruits checked had two pyrenes, but a few had three.

Giant Spotted Medick

I first noticed a giant form of Spotted Medick (Medicago arabica) in St Aidan's Nature Park (VC64) a few years back, where it is widespread, early into growth and achieving a high biomass early in the season, and it can form huge stands to the complete exclusion of pasture grasses. It flowers and fruits early and then dies back for the summer, before having a second flush in the autumn. Annoyingly though I have never been able to put a name to it, despite it having all the characteristics of a useful fodder variety. 

This year I have noticed it starting to spread out of St Aidan's, and have also found it widespread around the stables and horse paddocks at Royds Green (VC63). Clearly, someone is growing it and distributing it in wildflower seed mixtures and for agricultural use. 

Motivated to try again for a name, I've trawled Google and persevered against initial results indicating that this species is rarely cultivated and has no known cultivars. Eventually I stumbled on an old agricultural publication from 1951 (the thrillingly titled Harvesting and Cleaning Grass and Legume Seed in the Western Gulf Region). Finally someone acknowledges that three cultivars were developed in the United States (clearly so long ago that no one remembers their names) and one is called 'Early Giant'.  Could this be it? Well, details are thin but it was considered notable for its early growth and seed production, and it must be called 'Giant' for a reason. So that sounds promising and it will certainly do as a name for now. If anyone knows different please let me know.

Bottom Boat and Back

I made the most of the good weather on Tuesday to walkover over to Bottom Boat (VC63). Its not a route I do often, as it requires a bit of a slog up and over the ridge that separates the Aire Valley from the Calder Valley, but it does offer potential for interesting casuals and escapes and usually provides something of interest.

The day started well before I had even left Oulton with some particularly robust Cockspur (Echinochloa crusgalli) on an arable margin. This seems to have sprung from nowhere given I walk pass this field regularly.

Reaching my target destination I stumbled on a patch of derelict hardstanding with a variety of interesting garden throwouts. This is where I met 'Angelina' (see previous post). Other highlights included:

The golden form of Wilson's Honeysuckle (Lonicera nitida 'Baggesen's Gold').

Pink-sorrel (Oxalis articulata), in association with Stinking Hellebore (Helleborus foetidus) and surprisingly, as I did not know that it can throw up leaves in autumn, Garden Grape-hyacinth (Muscari armeniacum).

Stinking Tutsan (Hypericum hircinum).

Slightly further on, this attractive bi-coloured cultivar of Broad-leaved Everlasting-pea (Lathyrus latifolius 'Blushing Bride') was still going strong.

While an arable margin nearby had the winged form of Black-bindweed (Fallopia convolvulus var. subalatus). Supposedly less common than the nominate form, but that is not my experience.

Working my way down towards the River Calder I moved into abandoned former colliery land. Not the richest of habitats, it needs a few more decades yet, but still with interest and its great that no one has tried to 'restore' it. 

By the farm track on route was a young and apparently self-established tree of Cherry Crab (Malus x robusta), a variable group that perhaps includes plants of other origin. One of the characteristics of this species is that the individual apples are variable in terms of whether or not they retain their sepals. I think it likely that the fruit will colour further, they were in shade so a little behind.

Heather (Calluna vulgaris) is already starting to move in amongst the secondary birch woodland, a species that is very uncommon in the lowlands of Leeds and Wakefield.

But keeping with the theme of unusual non-natives there is also a thicket of sapling Broad-leaved Cockspurthorn (Crataegus persimilis 'Prunifolia'). No idea how that arrived, but it does not look planted. It proved the first of several interesting (at least to me) hawthorns.

Further on, the landscape architects had been in at some point in the last 30 years 'restoring' the landscape and creating 'native woodland'. Of course its nothing of the sort, rank MG1 grassland and the usual mix of false natives and lookalikes. Among these was a tree currently going by the name of Miyabe's Maple (Acer miyabei). The true species is of Japanese origin and, like Alan Leslie notes in Flora of Cambridgeshire, I think our plants are probably something else. The question is what? Potentially it is an unnamed alien form of Field Maple (Acer campestre), but possibly as with many planted 'native' hawthorns, dogwoods, Viburnums and hazels it could be of hybrid origin. Its a striking tree though, with large leaves, long petioles and large keys (glabrous in this case but they can be hairy). The second photo below contrasts it with typical field maple (var. campestre).

There was also Coralberry (Symphoricarpos orbiculatus) and  the hybrid hawthorn Crataegus x subsphaerica. The latter in this case had foliage closer to Common Hawthorn (Crataegus monogyna) but with clear hybrid vigour, but those elongate erect sepals give the game away.

One final hawthorn brightened the walk home. Check out the haws on this Common Hawthorn, c. 13mm long by nearly that wide. Living up to its name of var. splendens. These large fruited bushes occur here and there amongst more typical plants. I'm not quite sure what to make of them (valid variety or just chance?), but they make a stunning sight in the autumn sunshine. The bottom photograph compares it with more typically sized haws from a neighbouring bush.

Petrosedum rupestre 'Angelina'

A bit of zing on wasteground at Methley Lanes (VC63) this week in the form of this attractive cultivar of Reflexed Stonecrop. A nice find given it joins a select few records in the BSBI database attributable to Mick Crawley, and also because it is the only record for Northern England. One to look out for.

A Gaggle of Goosefoots

I'm pretty sure that's the correct collective noun, although perhaps it should be confusion or conundrum. As acknowledged in Stace, and as obvious to anyone who has ever looked closely, this is a notoriously 'plastic' group of plants, with Fat-hen (Chenopodium album) particularly so and in all honesty a dumping ground for anything that can not be placed within the other accepted species. How many of us have felt unhappy recording the latter once we have appreciated its extreme variation? I know I have.

So the question is then, can any variants be recognised that are consistent and more than just oddities of local occurrence? That is where Sell & Murrell's recent classification comes in. I don't think anyone, Sell included, would expect this to be the definitive statement on the genus. Sell acknowledged that the genus has suffered from a lack of serious attention, probably more so than any other element of the British flora. But there are historic collections of the genus available for reference that at least allow us to come back at this group with a fresh pair of eyes. That is really what the Sell & Murrell classification is setting out, a first draft classification to be tested further, and ideally tested in the field rather than via the herbarium sheet.

I've been pondering this since 2018. Not rushing to record, just getting a feel for the variation. This year has given more time to look and collect photographs to go with initial identifications. This was assisted by a warm start to the year meaning that my local populations developed early and developed their stem colour (which is not a given this far north, stem colour is almost certainly not to be relied on), and a delayed harvest due to the wet summer that gave more time than usual to look. 

Based on this, I am more and more confident that there are some distinctive entities that are worth recognition, certainly no less so than accepted species such as Probst's Goosefoot (Chenopodium probstii). It is these taxa I focus on in this post (as I understand them, feedback welcome). They are all relatively tall species that occur widely and seem relatively straightforward, especially when encountered as populations. They are species that are hard to define on paper (like so many species), but once seen in the field make sense. Hopefully others will have a look at their local populations and share details so understanding of this challenging group can solidify further.

Druce's Fat-hen (Chenopodium drucei)

Named of course for the eminent botanist George Claridge Druce. This is a distinctive species with ovate or rhombic lower leaves (sometimes irregularly dentate - these teeth are small), and typically comparatively long lanceolate obtuse to acute leaves in the upper part of the plant. The foliage is a rather dark dull green. The inflorescence is also distinctive (relative to some other species) being widely branching and drooping at the tip. Sell describes this species as 60cm tall based on apparently limited field experience of this species. Some populations I have found were taller than this, no doubt dependent on weather and growing conditions (and probably when it first germinated i.e. early or late season).

Lower leaves, note some have small teeth

Note that the upper foliage becomes more elongate (lanceolate)

Typical mature inflorescence

I have been finding this species widely scattered in arable districts south-east of Leeds (VC63 and 64) within walking distance from home (the limit of most of my botanical excursions this year). But still a reasonable geographic spread (red dots) covering more than one farm. Each grid square is a monad

Fallacious Goosefoot (Chenopodium fallax)

I found this medium to tall species in its 100's at the edge of a potato crop. Faced with such a large uniform population it seems inarguable. But it occurs more widely and seems relatively common. It has distinctive dark green foliage, of relatively large size and held in a characteristically drooping way such that the foliage looks dense. The distinctive leaves have a triangular central lobe and typically a pair of lobes at the base (perhaps better described as lobe-like teeth). The inflorescence is relatively lax (compared with other species) but not as lax as Druce's Fat-hen. The only similar (and more widely accepted) species in Sell & Murrell is Maple-leaved Goosefoot (C. acerifolium), but I am not convinced that the definition of that species matches the understanding of this species in other countries.

Typical foliage from bottom of plant to top (left to right)

Foliage

Arrangement of the inflorescence (upper plant is paler as it has set seed and is going over)

Eastern Fat-hen (Chenopodium pseudostriatum)

Another medium to tall species, and perhaps the most common. When this plant loses its larger leaves, as most fat-hen species do later in the season, it would be easily mistaken for Striped Goosefoot (Chenopdium striatum). That may explain its name. The latter species never has the large and obviously toothed leaves of this species, but you could easily envisage it as one of the potential parents of Eastern Fat-hen, and something like Fallacious or Probst's Goosefoot as the other parent.

The best jizz for this species is the pale green foliage, oblong to ovate and denticulate on the lower plant (but no basal lobes), and untoothed and linear to lanceolate towards the top of the plant. It is usually quite a narrow plant. The stem can develop prominent red striping (in a good year, this seems unreliable in Yorkshire where I have known this species for several years). The inflorescence is much more dense than in the above species.

Typical growth form and inflorescence

Typical foliage from bottom to top of plant, affinities with other species but the plant as a whole is very different

Probst's Goosefoot (Chenopodium probstii)

So having looked at the above, what about an 'accepted' species. Some might describe it as nondescript in comparison.

It seems genuinely rare so is probably only a casual. I have found it by a muck heap and on land disturbed for construction of a motorway service station. I would be far less confident in my ID if there was not some good herbarium material online to compare against. See here.

This can be a tall species, but I don't think this should be relied. The foliage is a relatively pale green and has a very blunt (rounded obtuse) apex. All leaves are toothed, can develop a red margin, and the lower ones hang on relatively long petioles.

Lower leaves

Upper leaves