‘Alexander’s what?’ you may well ask. Granted, it is a strange name for a plant, but it could be said to be ‘Alexander’s Parsley’, in the sense it used to be called the ‘Parsley of Alexandria’, the city in Egypt founded by and named after Alexander the Great. And it is there, around the Mediterranean and in the Middle East, where Alexanders has its ancestral, native home. The Romans knew and valued it as a pot-herb, with taste and consistency similar to the related celery, and took it with them in their colonisation of western Europe two thousand years ago.

When I became a botanist forty years ago, Alexanders was found in two main habitats. Firstly, it was well known in grassy areas and hedge banks in and around centres of Roman civilisation and subsequent monastic activity, a persistent relic of former times. Secondly, reflecting its southern origins and susceptibility to frost, it was known from a thin belt around the coasts of southern England, Wales and Ireland, thriving under the winter warming mantle of the sea.

At the time I was in Norfolk, and one could always tell when approaching within a kilometre or two of the coast in May, as the road verges switched from the white of Cow Parsley to the yellow-green of Alexanders flowers. The photo above shows just that transition, near Ringstead in north Norfolk, in 1983 (sorry for the poor quality). Of course all that has now changed with global warming/climate breakdown: Alexanders has spread out from these adopted homes and now occupies a near-continuous range across East Anglia, the Home Counties and the South-west Peninsula.

Perhaps surprisingly, here in Wivenhoe it is not all that frequent. The main population we have is on the verges of Anglesea Road, an unmade ‘back road’ out of town, and concentrated around the bridge across the railway line. Close to home, and thus within easy reach of a lockdown exercise walk, this year has seen us paying lots of attention to our Alexanders…

The flowers started to open early, before the end of March, a budburst which has advanced along with its geographic spread. The flowers are lovely in close up, a distinctive yellow-green, a colour that complements the pink streaking on the enlarged, ensheathing leaf-bases. And almost straight away the aromatic, musky aroma started to draw in insects. As with all umbellifers, the flowers are open to all manner of pollinators, especially flies and wasps, tiny flowers in large flowerheads providing an excellent early season nectar and pollen resource.

Hoverflies have been especially noticeable thus far, in particular one rather special one, the Spotty-eyed Hoverfly Eristalinus aeneus (just look at those eyes!): one of only two hoverflies with that eye-pattern in Britain, it is a specialist of the coastal fringes, especially in the south-east.

Later on, other hoverflies will include Rhingia campestris (just starting to appear as I write), with their distinctive elongated ‘snout’, and very soon the St Mark’s Flies Bibio marci  (and relatives) will be out and draping their flowers in long-legged embrace. The later-opening flowers in May will also likely be home to the picture-winged fly Euleia heraclei, lovely creatures to watch, flashing their bar-codes at each other in courtship dance. These spend their larval life mining the leaf-tissues, between the upper and lower surface, creating an obvious blotch-mine. And the crowns of flowers will become vantage points for Yellow Dung-flies Scathophaga stercoraria, a hunter of other flies attracted to the flowers to feed.

This last week, the most noticeable insects have been ladybirds, basking on leaves as well as flowers, where they may be supplementing their usual aphid diet with nectar and/or pollen. Not that all were feeding: making the next generation was the activity of the week! We found at least eight species on the 10 metre long Alexanders patch, some of them in a bewildering array of colour forms; it was particularly pleasing to see Two-spotted Ladybirds, as these seem to have become rather scarce in these parts since the arrival of the Harlequin Ladybird some 15 years ago.

And all that is just a small snapshhot of what our Alexanders, any Alexanders, is going to offer, entomologically – here are a few more:

One other noticeable feature of this plant is that it is very often infected with Alexanders Rust, a microfungus. Rusts are so-called because they cause lesions on the host plant, often liberally sprinkled with orange spore-producing bodies. Furthermore, this species also causes the host plant to twist and contort, forming a gall.

Notwithstanding its value to passing insects, given the potentially invasive nature of Alexanders and its non-native status, it is perhaps a pity that more folk don’t eat it. The whole plant is edible, from roots and stems to leaves and flower buds, and even the dried, black seeds which can be ground up into a mild, aromatic ‘pepper’.

That may well be because it is not actually very pleasant….the celery/angelica notes, with rather oily spiciness (hence it is believed the origin of its scientific name Smyrnium, alluding to its myrrh-like qualities) is largely lost with cooking and my recollection is of pretty tasteless mush. But, if a suitable recipe could be developed, perhaps using also the mild garlic of that other invasive verge plant Three-cornered Leek, ‘eating the landscape’ could actually do a lot of good for conservation by keeping the invaders at bay.

One of our last blogs covered the plants of a microhabitat, dry grassland, found as discrete islands amid a sea of marshland on the top of ant-hills. Each one is unique, reflecting the uncertainties of colonisation of any of the species: chance plays a huge role in shaping the world around us.

Exactly the same, possibly even more so, can be said of today’s microhabitats, even closer to home for us, the array of 2cm-diameter bolt-holes on the timbers of the Shipyard jetty.

Lockdown changes perceptions, giving us the luxury of being able  to look closely at that which we have walked over uncomprehendingly for years. Colonised by a range of different mosses and lichens, each and every faerie garden is absolutely unique, a miniature of natural art.

And moreover, a natural experiment, just waiting to be investigated. A whole series of transects, in two dimensions (distance from the shore, and running at a right angle, distance from the edge, the latter probably significant in terms of trampling, salinity and nutrient status given the propensity of Black-headed Gulls to sit on the rails)…

… and if the lockdown continues long into the summer, that might just be one of our sanity projects. Something which could produce valuable scientific evidence related to the the theories of island biogeography and colonisation, of such importance to understanding how we might encourage recolonisation of our nature-depleted landscape.

Just downstream of Wivenhoe lies Barrier Marsh, an area of typical Essex grazing marsh. Formerly tidal saltings, the influence of the tide was removed several centuries ago by the creation of the sea-wall, a coastal defence aimed at facilitating agricultural grazing of the land behind. Now it is a Site of Special Scientific Interest, notified especially for the nationally scarce plants it supports and for the diversity of ditch plant communities found there. But one of its most significant features is overlooked by the designation: stand on the sea wall and look across the marsh, and the overwhelming impression is of an undulating sea of grassy mounds – the nests (ant-hills) of the Yellow Meadow Ant Lasius flavus.

The marsh is bisected by The Chase, a track running on a bund from higher ground. This is actually in a sliver of the otherwise landlocked historic parish of Elmstead, giving access to tidal waters between its neighbours, Wivenhoe and Alresford. Most of the larger ant-hills (up to 50cm high) are east of the The Chase, suggesting this is ‘virgin’ grazing marsh, while to the west, the surface is more level, the hills are fewer and smaller, possibly indicating that this side was ploughed in the past, perhaps during World War 2. Taken together, a back of an envelope calculation suggests that there are between ten and twenty thousand large hills on this marsh, and as each nest may support up to 5,000 ants, that’s an awful lot of ants…

So why were we out looking at ant-hills as our permitted lockdown exercise? Simply, they are endlessly fascinating – each hill is different, an island of aerated, sandier soil in a sea of waterlogged marshland. Each microcosm has a different range of plants that have colonised it, probably related the to the size (age) of the ant-hill and the distance of the hill from the ‘mainland’ (The Chase), but also influenced by random colonisation events.

So, as the photos here indicate, each ant-hill is unique, and together they support a range of species one would not expect to find in a marshland context: Sticky Mouse-ear, Sheep’s Sorrel, Small Forget-me-not, Wall Speedwell, Groundsel, Early Whitlow-grass and Hairy Bittercress, and the cup lichen Cladonia fimbriata. In other words, an archipelago of mini-heathlands.

Two plants deserve special mention. One is the nationally scarce Divided Sedge, one of the features for which this site is designated SSSI. This is widespread right across the site, but on the anthills, it was already in flower, incredibly early in the season for that which I normally associate with May. Conversely, something flowering when it should but not where I would expect it was the Early Meadow-grass on just a couple of ant-hills, a plant I have never seen before around Wivenhoe, nor indeed in Essex away from Thames-side.

The hills in general looked very healthy, with only a few crumbling away after a colony has died. When the sea wall overtopped in the tidal surge of December 2013, much of the marsh was under a metre of water for a couple of weeks, and I was worried for the future of the ants. Presumably they are able to tolerate some degree of inundation: in winter they retreat into the heart of the hill, when there may well be air-filled chambers, enough for some of the colony to remain alive.

Even now, at the end of March, it is likely the ants are deep down, albeit not down as far as the waterlogged marsh soils. We certainly saw none. Although, unless you deliberately dig into a Yellow Meadow Ant-hill, there are not often seen. They have little need to come to the surface and run the gauntlet of insectivorous birds, as for the most part they feed on honeydew excreted by aphids which live on the roots of the plants of the ant-hill!

As long as we are in lockdown, I suspect we shall continue to visit our ant-hills regularly. As the nests awaken from their winter torpor, perhaps we will even manage to find  something I have looked for for years but without success: the tiny, while, blind woodlouse Platyarthrus hoffmannseggii, which lives its life in these ant-hills. But to damage a hill in this quest would be a travesty of natural justice: I guess we will simply have to wait until we see a Green Woodpecker digging into a nest in search for food…

And to cap it all, a month later we came upon one, just one among thousands so far as we could ascertain, ant-hill with a couple of plants of the nationally scarce and fascinating Mousetail.