Salix phylicifolia L., Tea-leaved Willow
Account Summary
Native, but a mis-identification. Eurosiberian boreo-temperate.
1990; Montgomery, J. & Foster, S.; Castle Caldwell FNR, swamp and carr.
This is regarded by us as a clear case of mis-identification. The EHS Habitat Survey recorders who believed they found this very rare willow wrote the species name on their record card rather than ticked a box. However, they did not appear to realise that S. phylicifolia is such a rare species, that any new record requires a voucher, and after expert verification it would then deserve separate publication in the Irish Naturalists' Journal.
Irish specimens of this species were previously referred to as S. hibernica Rech. f., but the current view of most botanists in B & I familiar with the group is that S. hibernica is not sufficiently distinct and that it can be accommodated within S. phylicifolia. However we name it, this shrub is known in Ireland from only two damp limestone mountain cliffs on the Ben Bulbin range in Cos Sligo and Leitrim (H28 & H29). The willow populations there are chiefly on cliff 'slips', which originally formed part of the face of the main cliffs but which have slid downwards sometime in the current post-glacial period. These slips now appear either as cliff stacks, separate but close to the main cliffs, or else they lie slumped at the base of the original cliff. These cliffs and slips carry a rich assemblage of relict alpine plants. It is thought by some botanists at least, that the alpines and this willow survived here in situ on surfaces that were high enough to protrude above the glacial ice during the previous cold period (Stelfox 1965; Synnott 1983). Personally, the current author finds this hard to credit, although there is evidence that suggests one or more nearby refugia may have existed (see Vegetation History in The Flora of County Fermanagh) (Forbes & Northridge 2012).
The habitat of the questionable Fermanagh record at Castle Caldwell was listed as swampy fen-carr woodland, which in view of the above is completely inappropriate for S. phylicifolia. Other mistaken 19th century records have previously been claimed for VCs W Mayo (H27), W Donegal (H35), Antrim (H39) and Londonderry (H40). The surviving vouchers for the latter are of, "remarkably poor quality" (Stelfox 1965), but have been re-determined as shiny-leaved forms of S. cinerea subsp. oleifolia (Common Sallow) (given away by the presence of a few characteristic brown hairs on the leaf under-surface), or rarely as S. myrsinifolia Salisb. (= S. nigricans Sm.) (Dark-leaved Willow), or possibly its numerous hybrids (Synnott 1983).
On these grounds, we must discard the Castle Caldwell finding of S. phylicifolia. Unfortunately, there is no voucher specimen so we cannot clarify how or why the error was made, but most probably the plant was a form of the extremely variable sally, S. cinerea subsp. oleifolia.
In Britain, S. phylicifolia is a very much more widespread species, but even here it is predominantly a Scottish plant of waterside habitats on moist rocky ground. It is also found in England as far south as Lancashire and Yorkshire. It occurs at altitudes from near sea-level to 670 m in the Highlands (Meikle 1984). S. phylicifolia is widespread in Scandinavia and Iceland, where it appears indifferent to soil reaction. It is the dominant Salix species in middle and north boreal riverbank communities, being frequent in abandoned damp pastures and meadows, plus along roadsides (Jonsell et al. 2000).
Growth form, appearance and preferred habitats
The conspicuously ear-shaped stipules and the entire or sub-entire (ie scarcely toothed) leaf margins, the sometimes obliquely twisted leaf tip, the leaves at first coated on the upper surface with silky, white, adpressed hairs and the small size of the sprawling plant are all important recognition features. The habitat is acidic or slightly base-enriched heaths and moors, or in limestone grassland, occurring where the parent species overlap, although as with other willow hybrids, more often where one parent is more common than the other, rather than where they are equally represented (Willows and Poplars Handbook).
Fermanagh occurrence
There is only one record for this low, sprawling hybrid in our Fermanagh Flora Database made by Meikle and his co-workers on Lough Melvin near Garrison. It is undated but must fall sometime in the immediate post-war period of this group's regular summer visits. In his BSBI Willows and Poplars Handbook, Meikle (1984) regarded this hybrid as being frequent in B & I, so perhaps it is being regularly overlooked.
Irish occurrence
The FNEI 3, published eight years after the Willows and Poplars Handbook, lists ten records of this hybrid from Co Antrim (H39), all of which were made by one recorder, John Harron, during the 1970-88 period. The FNEI 3 account describes S. × ambigua as being, "frequent and widespread on the Antrim Hills". However, the Flora of Co Dublin makes no such claims regarding this subshrub, merely mentioning that a previous record (no details) was not refound on Mountpelier in District 7 of the Flora. The Irish representation of this hybrid is very poor, with just six hectads in Co Antrim (the Harron records mentioned above), and solitary hectads in four other Irish VCs, Co Kildare (H19), E Mayo (H26), Co Fermanagh (H33) and W Donegal (H35).
British occurrence
Despite Meikle's assertion that this hybrid is of frequent occurrence, the New Atlas hectad map demonstrates only a thinly scattered record of S. × ambigua exists across northern parts of B & I, with a quite marked Scottish predominance, especially on the N & W Isles. The hectad map in the Hybrid Flora of the British Isles shows a considerable increase in records right across both B & I, but the pattern of scattered sites is similar, although with more hybrid presence in the S of England. It is described by these authors as, "one of the commoner willow hybrids in northern Britain, particularly near the west coast where the parents often grow in close proximity in exposed coastal heathland and moorland" (Stace et al. 2015).
Clearly, a greater and much more focussed recording effort is required to ascertain the true extent of this hybrid, but Howitt & Howitt (1990) point out the significant and relevant fact that S. repens (Creeping Willow) flowers later than S. aurita (Eared Willow) (ie usually about the end of April), which obviously time-limits the opportunity for cross-fertilisation. The northern distribution of the records in B & I may reflect a modification of the timing of flowering of these willow species, perhaps significantly increasing the period of overlap and enabling a greater frequency of crossing.