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1
Brief observations of vegetation following a re on Flagstaff , Dunedin
John Barkla (mjbarkla@xtra.co.nz)
On Monday 16 September 2019 a re swept through c. 30 ha of montane tussock-
shrub/ axland on the popular Pineapple Track that traverses Flagsta (668 m) above
Dunedin. Billowing smoke and ames were clearly evident from the city and it took
eight helicopters and 35 remen to contain the re. Dampening down continued
through Tuesday, and surveillance of hot spots was ongoing for several days. e
Pineapple Track was closed for a week.
Evidence from sub-fossil logs suggests there was a cover of montane forest on Flagsta
until about 1300 AD. Chionochloa rigida-dominant tussocklands are thought to have
been present since at least the mid 19th century and maintained by periodic res
(Wardle & Mark 1956). A hot spring re in late 1976 burnt c. 100 ha. Given its close
proximity to Dunedin, the area around Flagsta has been a convenient research site
for investigating the e ects of re on snow tussock, e.g. Gitay et al. (1991).
I walked through the burn site on 28 September, almost two weeks a er the re
started (Fig. 1). As expected, it was a scene of blackened devastation (Figs. 2 & 3) with
bare charred rocky ground punctuated by tussock and ax stumps and burnt stems of
exotic broom and native shrubs.
Figure 1 (top). View east towards Dunedin over south-facing burnt slopes, September 2019.
Figure 2 (above le ). A bare charred tussock- ax-shrubland, September 2019.
Figure 3 (above right). Burnt ax, September 2019.
NO. 198
May 2020
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NEW ZEALAND
PLANT OF THE MONTH, p. 3
Poa antipoda. Photo: Rowan
Hindmarsh-Walls
TRILEPIDEA
Newsletter of the New Zealand Plant Conservation Network
2
I returned to the burn site on 25 April 2020, some seven months or one growing season later (Fig 4).
Mountain ax or wharariki (Phormium cookianum) has universally survived and vigorous regrowth
was clear (Fig 5). Some snow tussocks have perished but the majority have survived, as evidenced by
modest new tiller growth. Near the lower altitude margins of the burn some native shrubs, especially
Olearia arborescens, have resprouted extensively from their bases (Fig 6).
Figure 4 (top). View east towards Dunedin over south-facing burnt slopes, April 2020.
Figure 5 (above le). Recovering ax, April 2020.
Figure 6 (above right). Tussock hawkweed with basal resprout of Olearia arborescens behind, April 2020.
Much of the previously burnt bare ground has been colonised by a range of native and exotic plants.
Common native species include mountain astelia (Astelia nervosa), prickly shield fern (Polystichum
vestitum), mountain kiokio (Blechnum montanum), and alpine clubmoss (Lycopodium fastigiatum).
Common exotics include a range of pasture grasses, especially browntop (Agrostis capillaris) and sweet
vernal (Anthoxanthum odoratum), catsear (Hypochaeris radicata), tussock hawkweed (Hieracium
lepidulum), and swathes of seedling exotic broom (Cytisus scoparius) and gorse (Ulex europaeus). Burnt
tussock stumps in particular seem to be favoured establishment sites for wild broom seedlings.
ere are encouraging signs of recovery of native species, including some structural dominants, and it
seems inevitable that the vegetation will rapidly transition towards its pre-burn state. at vegetation,
without intervention, is likely to include a signicant and increasing component of woody weeds such
as exotic broom and gorse.
References
Gitay H, Wilson JB, Lee WG, Allen RB 1991. Chionochloa rigida tussocks 13 years aer spring and autumn re, Flagsta,
New Zealand. New Zealand Journal of Botany 29: 459–462.
Wardle, P & Mark, A. 1956. Vegetation and Climate in the Dunedin District. Transactions of the Royal Society of New
Zealand 84: 33.
Figure 7. Exotic broom seedlings established on burnt
tussock stump, April 2020.
3
PLANT OF THE MONTH – POA ANTIPODA
Rowan Hindmarsh-Walls
The plant of the month for May is the sub-antarctic grass, Poa antipoda, one of about seven
species of native Poa found in the New Zealand sub-antarctic region. The species is found on
Auckland, Campbell and Antipodes Islands, as well as Herekopere Island o Rakiura.
Poa antipoda, Falla Peninsula, Auckland Island, January 2020; (le) growth habit, (right) inorescence.
Poa antipoda typically occurs on clis and rocky outcrops, both on the coast and inland. It prefers
damp places, often within the dripline at the bottom of blus. The species is moderate in size
and bright yellow-green with soft, at leaves. The owering culms are usually open, with 3–4
owered spikelets that are green with pinkish-red tips. Like other Poa species, Poa antipoda has
soft membranous ligules.
This species is somewhat similar to a few of the other sub-antarctic Poa, namely P. foliosa, P.
ramosissima and P. tennantiana. P. foliosa diers from P. antipoda by being more robust and much
larger in size (up to 1.5 m compared to 20–60cm). P. ramosissima has lacerate ligules while P.
antipoda has entire ligules and P. tennantiana has plants that are stout and sti-leaved, unlike the
soft drooping leaves of Poa antipoda.
Poa antipoda is endemic to the New Zealand region and has a threat ranking of “At Risk –
Naturally Uncommon” due to its restricted distribution in the New Zealand sub-antarctic region.
On some of the sub-antarctic islands, the species is possibly threatened by competition with
exotic grass and herb species. On Auckland Island, seed predation by mice is a potential factor
limiting its spread.
The name Poa is the Greek word for meadow-grass or fodder. The species epithet antipoda means
Antipodean, of the Antipodes Islands.
You can view the NZPCN website factsheets for Poa antipoda at:
https://www.nzpcn.org.nz/ora/species/poa-antipoda/
4
Lockdown musings on scurvy grass (Lepidium oleraceum)
Peter J. de Lange (pdelange@unitec.ac.nz), School of Environmental & Animal Sciences, Unitec Institute
of Technology, Auckland
In the dim dark days when we still had Standards and Forms in New Zealand schools, my Standard 4
class studied Captain James Cook (1728–1779) and aspects of his ‘discovery’ of Aotearoa / New
Zealand. My memory of the lessons, some 43 years later is of course vague but I do recollect in the
school journal a lithograph of a plant called ‘Cook’s scurvy grass’. Fledgling botanist that I was then
this intrigued me. Aer all, the illustration of the plant so named looked more like a herb than a grass
to me. I wanted to know more about it of course but all I gleaned from the journal story was that Cook
instructed his crew to harvest lots of it, which he then fed, willingly or not, to them, so saving them
from scurvy.
Further reading later deduced that ‘Cook’s scurvy grass’ was not a grass at all but rather a kind of
cress in the genus Lepidium, L. oleraceum, allied to the cress plant Lepidium sativum which we used
to grow with mustard (Sinapsis arvensis) and then use as a sandwich lling. Cook it transpired used
the vernacular ‘scurvy grass’ because in his childhood he and his father went out foraging for ‘scurvy
grasses to supplement the family’s diet. While they
had a broad denition of ‘scurvy grass’ then, the
name was mostly applied, as it still is, to species
in the brassicaceous genus Cochlearia (Fig. 1). As
for me, I pretty much forgot all about scurvy grass
until 1981, when wandering through a book shop
in Wellington, I found a lovely book called ‘Rare
and Endangered Plants of New Zealand’ that had
just come out for sale. at book was written by
the late David Given (1943‒2005), and in it there
was a colour picture of ‘Cook’s scurvy grass’. Given
(1981) noted that the plant was endangered with
extinction, repeated the tale about Cook using it
to cure scurvy, and then oered some reasons for
its demise. Like the school journal before, Given
repeated the story that Lepidium oleraceum was
once really common throughout New Zealand;
common enough that Cook’s crew could collect
whole boat loads of it to make into scrumptious,
life-saving, salads.
My rst hands-on experience of Lepidium oleraceum came by accident in 1985 whilst engaged in a
second year University of Waikato Earth Science undergraduate paper that required eld work whilst
based at Port Waikato. One exercise involved mapping a coastal exposure at Ngatutura Point. Ngatutura
is located c.24 km south of Port Waikato, near the Kaawa River mouth on the rugged western Waikato
coastline. ere, whilst struggling up and down the cli faces, sketching, sampling rocks and taking
strike and dips I was amazed to nd some Cook’s scurvy grass. at plant grew near the top of the
point in coastal turf, close to a towering near shore stack known as ‘Shag Rock’, on account of a spotted
shag (Phalacrocorax punctatus) colony that bred there. Binoculars soon conrmed that the plant I
found was probably derived from Shag Rock, where I could see many more growing in crevices below
and around the shag nests. I have since had the joy of seeing this plant and its close allies wild in an
array of places spanning from Dayrell Island in the Kermadecs to Otago Peninsula and the Chatham
Islands.
At the time Given (1981) wrote about it, Lepidium oleraceum was a name applied in a very broad sense.
Indeed, almost from the time it was rst described by Anders Sparrman (1780) the species was known
Figure 1. One of the European scurvy grasses, Cochlearia
ocinalis, seen here at Friesetraatweg, Groningen,
Netherlands. Species of Cochlearia were (and still are)
eaten by Europeans as a salad herb. Photo: A. Hospr.
5
to be ‘variable’ resulting in attempts to segregate that variation into taxonomic units. Pioneer botanist
omas Kirk (1828‒1898) for example, described two varieties Lepidium oleraceum var. acutidentatum
Kirk, and var. frondosum Kirk (Kirk 1899), and Albert ellung (1881–1928) recognised another,
var. serrulatum ell. (ellung 1906). However, by the time Harry Allan (1882–1957) assessed the
situation the application of these names had become confused (Allan 1961), in part because the
species was already in such serious decline that Given (1981) pessimistically attested that resolution of
these names based on what was le in the wild was likely now impossible. However, critical study of
Lepidium oleraceum throughout its range, supplemented with DNA based phylogenetic analyses and
patient study of the type specimens scattered around the world has resulted in a new interpretation
of the species (de Lange et al. 2013). at monograph redened Lepidium oleraceum, to encompass
those plants with glabrous (hairless) stems, persistent, toothed, stem leaves, glabrous pedicels, owers
with four stamens and by the acute silicles which lack a marginal wing (de Lange et al. 2013) (Fig. 2A–
F). Plants matching these characters are known from the Kermadec Islands, North Island, northern
South Island and Chatham Islands. In the same treatment other plants that had been referred to L.
oleraceum were split into a further 10 species: L. aegrum Heenan et de Lange, L. castellanum de Lange
et Heenan, L. crassum Heenan et de Lange, L. juvencum Heenan et de Lange, L. limenophylax de
Lange, B.D.Rance et D.A.Norton, L. oblitum Houliston, Heenan et de Lange, L. oligodontum de Lange
et Heenan, L. panniforme de Lange et Heenan, L. rekohuense de Lange et Heenan and L. seditiosum de
Lange, Heenan et J.Rolfe (see de Lange et al. 2013).
Figure 2. Lepidium oleraceum in cultivation, Mt Albert, Auckland, showing diagnostic characters of this species: (A)
Foliage, (B) Flowering plant, (C) close up of foliage, owers and immature fruits, (D) owers showing the four stamens
that help distinguish L. oleraceum from other allied species in New Zealand, (E) mature and immature silicles – note the
lack of a marginal wing to the silicles, the acute silicle apex and lack of any notching, and (F) mature silicle and glabrous
pedicel. Photos: P.J. de Lange.
A
D
B
E
C
F
6
Taxonomy aside though, that research also uncovered a wealth of information and misinformation
about ‘Cook’s scurvy grass’.
e rst of these, that still needs further research, is the vexed question of whether Māori cultivated
Lepidium species. Long before the moniker ‘Cook’s scurvy grass’ was ever coined iwi knew Lepidium
oleraceum and its allies by the name ‘nāu’. is name is potentially signicant, aer all it is not unique to
New Zealand; it is used for example by Cook Islanders for the supercially similar Lepidium bidentatum
Montin (Fig. 3A, B), and the name and variants of it appear throughout Polynesia for that species and
other allied lepidia. Discussions with the late Art Whistler (1944–2020) in 2010 helped conrm what
I had long suspected, that Lepidium bidentatum was not used solely as a vegetable by Cook Islanders
but rather that it was generically used throughout Polynesia, notably in Samoa and Tonga and the
Society Islands. It should therefore be no surprise that Lepidium oleraceum was bequeathed the same
name by those voyagers destined to become Māori. Now while I have never found convincing proof
that Māori deliberately grew it, comments about its abundance near Māori settlement made by the
Forster’s (Forster 1777; Hoare 1982) and observations by Joseph Banks, Daniel Solander who rst
collected it in New Zealand, and Captain James Cook suggest that iwi certainly ate it (Beaglehole
1962a, b; 1967, 1968) and that they probably did cultivate it. In a modern sense I have always felt that
the widespread usage by Māori of watercress (Nasturtium microphyllum and N. ocinale) as a salad
green and vegetable reects past mātauranga reecting the historical usage of nāu and perhaps also
Rorippa divaricata. is needs further study.
Figure 3. Lepidium bidentatum (in this case var. owaihiense) as seen on Maui in the Hawaiian Island group. is close
relative of Lepidium oleraceum was once wide ranging across the eastern Pacic where it was well known to many
Polynesian islanders as a vegetable and medicine. Photos: F. & K. Starr).
e second issue, which David Norton and I revisited in 1996, is whether folklore that Cook collected
‘boatloads’ of Lepidium oleraceum for use as a salad green to save his crew from scurvy is fact or
ction (de Lange & Norton 1996). If you remember, as a 10 year-old I learned that Cook instructed
his crew to collect scurvy grass, which they found in sucient quantities to collect in ‘boat loads’ to
sustain his hungry crew during their exploration of New Zealand. is story is widely accepted as
fact (see for example Moore & Irwin 1978), and has been used by such authorities as omas Kirk,
A B
7
omas Cheeseman, Lucy Moore and David Given as evidence that the formerly abundant Lepidium
oleraceum had suered a catastrophic decline that started soon aer Europeans began to settle the
country (Cheeseman 1914; Kirk 1899, Given 1981; Oliver 1925; Richards 1956; Moore & Irwin 1978;
Wilson 1982; Wilson & Given 1989).
at Lepidium oleraceum was once more abundant than it is now is evident from past accounts by early
voyagers, naturalists and resident botanists. However, critical assessment of the primary literature,
namely the journals of Captain Cook, Joseph Banks and the Forsters does not support the notion
that they were able to collect boat loads of Lepidium oleraceum (de Lange & Norton 1996). What they
did collect is a suite of edible coastal herbs, including Apium prostratum, Cardamine spp., Oxybasis
ambigua, Salicornia quinqueora, Te t r a g o n i a implexicoma, T. tetragonoides, and the brassicaceous
herbs Lepidium exicaule, L. oleraceum, Rorippa divaricata and R. palustre (de Lange & Norton 1996;
Norton et al. 1997; P.J. de Lange unpubl. data). e only place those early accounts noted Lepidium
oleraceum as abundant was Queen Charlotte Sound where it was considered common on a few islands,
notably Long Island (interestingly the Sounds remain a stronghold for Lepidium oleraceum). What
seems clear is that Cook instructed his scientic ocers and naturalists to look for edible plants, and
once these became known to the crew, they were widely collected as a dietary supplement.
Of these, the one plant the crew preferred to eat however, was Lepidium oleraceum. Consider the
comments of Anderson, a surgeon on Cook’s third voyage, ‘Of other plants which were useful to us may
be reckon’d wild celery which grows plentifully almost in every cove, especially if the natives have ever
resided there before, and one which we us’d to call scurvy grass though entirely dierent from the plant we
gave the name to. It however is far preferable to it for common use and may be known by its jagged leaves
and small clusters of white owers on the top’ (Beaglehole 1967: 804).
Anderson’s remarks are not only an apt description of Lepidium oleraceum, this is also the rst time
that the vernacular scurvy grass is directly associated with that species. However, the rst usage of
‘Cook’s scurvy grass’ seems to have come much later, about the time of Kirk (1899). So the widespread
belief that Cook’s scurvy grass was once so common it could be collected by the boat load really has
no basis, rather it was one of a number of plants used by Cook and his crew and over time the broad
concept of ‘scurvy grass’ was narrowed to Lepidium oleraceum which eventually became the ‘C ook’s
scurvy grass’.
Lastly there is the matter of the decline of Lepidium ole raceum itself. What caused it? We do know that the
New Zealand archipelago was once dominated by seabirds (Fig. 4), and these birds played a critical role
in bringing nutrient from the sea to the land. is system, dubbed the ‘ornithocoprophilous ecosystem’
(work that one out) by Bob (Robert) Orndu (1932–
2000) (Orndu 1965; Norton et al. 1997) received
scant attention by New Zealand ecologists until the
late 1980s, when it was ‘rediscovered’ (Ogle 1987). For
our early understanding of the system we owe much
to the pioneering work of Leonard Cockayne (1855–
1934) who described the vegetation patterns of many
predator free seabird islands but especially to Mary
Gillham (1921–2013) who had a particular interest in
these associations, and who in a series of landmark
papers (Gillham 1956, 1960a, b, 1961), some prepared
whilst on study leave from the United Kingdom in
New Zealand, documented the distinct vegetation
associations found on the so called ‘sea bird islands’
o our shoreline. Her work and that of Bob Orndu
noted a distinct correlation between particular plants
and seabird nesting sites. Some species they reasoned
Figure 4. Adult masked boobies (Sula dactylatra
tasmani) roosting on North Chanter, Herald Islets,
northern Kermadec Islands group. ese birds and
others that nest and roost on this island are part of an
intact and functional ornithocoprophilous ecosystem,
that was once widespread throughout the adjacent
New Zealand Archipelago. Photo: P.J. de Lange.
8
were utterly dependent on sea birds to maintain their habitat and perhaps for their growth and
persistence. One of those plants was Lepidium oleraceum sens. lat.
Norton et al. (1997) reasoned that, following the colonisation of the New Zealand archipelago by
humanity, the subsequent spread of introduced mammalian predators resulted in range contractions
and local extirpations of the vegetation associated with seabirds. ey concluded that this contraction
meant that plants such as Lepidium olerace um were already in decline by the time they were rediscovered
and formally described by European botanists. However, they also reasoned that in those places where
the ornithocoprophilous ecosystem remained intact the vegetation associated with that system would
persist. What they noted was that in such places while this was true there continued to be local
extirpation of key species such as Lepidium oleraceum sens. lat. So seabird decline whilst a factor was
not the sole reason for the decline.
Kirk (1891) and Cheeseman (1914, 1925) attributed declines to direct browse pressure by sheep (Ovis
aries) and cattle (Bos taurus taurus), Norton et al. (1997) suggested that rats (Rattus spp.) also have
impacted the species through the direct browse of plants (indirectly rats are a key factor in that they
contributed to the decline of seabirds). It is also evident that possum (Trichosurus vulpecula) are now
a factor impacting members of the Lepidium oleraceum group throughout accessible sites in the North
and South Islands and on Rekohu (Chatham Island). Esler (1975) and Given (1981) amongst others
attributed an acceleration of decline to the accidental
introduction of cabbage white butteries (Pieris
rapae) to New Zealand, it is thought, over the summer
of 1929–1930 (it was ocially recognised here in 1930
from specimens collected from Napier). As anyone
who has grown Lepidium oleraceum will appreciate,
cabbage white butteries are a real pest (Fig. 5.) but
there are others. For example, Ogle (1987) noted the
impact of cabbage aphid (Brevicoryne brassicae) and
diamond backed moth (Plutella maculipennis) as well
as a host of other introduced invertebrates. It cannot
be doubted that these introductions have contributed
and continue to contribute to further losses.
e conclusion reached by Norton et al. (1997) was that to retain Lepidium oleraceum populations
it is critical to retain seabird breeding grounds. ey reasoned, in line with the thinking of others
such as Mary Gillham, that seabirds and seals contributed both nutrients and disturbance, so keeping
sites open. Recently Dale et al. (2017) explored whether seabirds were essential to facilitate seed
germination in Lepidium, discovering that seed germination was not promoted by seabird guano
but that the seeds are probably dispersed by seabirds. ey discovered that wetted seed releases a
mucilage which enables seed to adhere to surfaces for over 24 months. at discovery may explain
how Lepidium oleraceum in particular has such a wide geographic spread. It also shows that the overly
simplistic assumptions of the importance of the nutrients le by seabirds and seals in promoting
seed germination, growth and population resilience need further research. Nevertheless, as anyone
who has tried growing Lepidium oleraceum will appreciate, plants ourish with regular applications
of Nitrogen, Phosphorus fertilisers, and some gardeners use such fertilisers as a way to control the
damaging eects of ‘white rust’ (Albugo) (Fig. 6A, B), noting that well fed plants seem to ‘out-grow’
the disease. e same logic has been employed by the Department of Conservation with managing
Lepidium banksii and L. rekohuense, whereby plants are routinely ‘over fertilised’ to help them thrive
in the wild (P.J. de Lange unpubl. data).
So what is the deal with Albugo? at organism has over the last 20 years become a major concern
when managing Lepidium populations (Norton & de Lange 1999). Albugo is actually not a rust at all
rather it is an oomycete, so more closely related to Phytophthora for example, nevertheless it is widely
Figure 5. Cabbage white buttery caterpillar (Pieris
rapae) on Lepidium oleraceum. Photo C.C. Ogle.
9
A
B
Figure 6. Albugo candida infecting (A) shepherd’s purse (Capsella bursa-pastoris) (Te One, Rekohu / Wharekauri / Chatham
Island) and (B) rocket (Eruca sativa subsp. vesicaria) (Mt Albert, Auckland). Photos: P.J. de Lange.
known as ‘white rust’ on account of the white pustules it produces during its reproductive stage. Albugo
is now widely acknowledged as a serious threat to New Zealand indigenous Brassicaceae, and, in
particular Lepidium (Norton et al. 1997; de Lange et al. 2013). Albugo is most evident when the white
pustules appear but it has been discovered that it commonly occurs as asymptomatic infections with
one study noting it present in a range of apparently healthy Lepidium oleraceum plants spanning that
species range (Armstrong 2007). Albugo pustules may appear all over an aicted plant, however, they
are most commonly seen on young foliage and inorescences (including ower buds, owers) and
developing fruits (Fig. 7), thus reducing the host plants ability to thrive and reproduce. Death from
severe Albugo infection has been reported in wild populations of Lepidium banksii, L. oligodontum and
L. panniforme (de Lange et al. 2013). Despite a range of treatments, none used to date can truly be said
to be eective, and some, such as the use of the fungicide Ridomil Gold® that is used in the treatment
of some oomycete diseases, while slowing the visible
pustule stages of Albugo are not in the long-term
environmentally suitable for use in natural habitats.
Worryingly, reports of Albugo attacking New Zealand
indigenous Brassicaceae have increased in the last
three years, with some seriously threatened species
such as the South Island salt pan endemic Lepidium
kirkii Petrie, and dioecious L. sisymbrioides Hook.f.
and L. solandri Kirk now possibly in terminal decline
because of this disease. Until recently the Albugo
aicting our indigenous Lepidium was assumed to be
A. candida (Pers. ex J.F.Gmel.) Kuntze. is follows on
from the only comprehensive study of the genus in
New Zealand undertaken, that by Baker (1955). In
that paper she treated what we now call A. candida as
A. cruciferarum S.F.Gray, and considered it introduced
on the basis that it was rst recorded from New
Zealand by William Colenso in 1886. To counter this
view though is the fact that few people were at that
time actively collecting these sorts of organisms, so it
may have been here longer, possibly naturally so.
ere have even been some doubts raised as to
Figure 7. Lepidium oligodo ntum plant severely infected
by Albugo (Moriori Creek, southern tablelands,
Rekohu / Wharekauri / Chatham Island). Photo: P.J.
de Lange.
10
whether the Albugo reported from New Zealand is actually A. candida; judging by its presence
throughout the range of New Zealand’s indigenous lepidia, and the life cycle of some species such as
L. oligodontum that seem to ‘t around’ the impact of this disease (de Lange et al. 2013). As such a
revisit into the taxonomy of Albugo here has long been desired.
Recently, Dr Jerry Cooper of Landcare Research has
been investigating those infections attributed to Albugo
candida, notably in the South Island inland dioecious
lepidia, L. sisymbrioides and L. solandri. Using DNA,
Cooper has discovered that the Albugo infecting
these two species is not A. candida but A. lepidii
A.N.S.Rao (Fig. 8), and as a result of that discovery
Jerry expanded his research to cover Chatham
Islands lepidia, including L. oleraceum, nding the
same Albugo species was involved (see for example,
https://inaturalist.nz/observations/24541077). Jerry
also found that Albugo candida is in New Zealand
but that it attacks other exotic Brassicaceae. It would
seem that Albugo lepidii is also introduced. Hopefully
this knowledge may enable better management of the
disease in the wild.
So returning to the original question of what caused / is causing the decline of Lepidium oleraceum in
New Zealand? e answer is linked to the historical collapse of the ornithocoprophilous ecosystem,
resulting in population fragmentation and loss of functionality, followed by a steady increase of
pressures on remnant populations from introduced predators, weeds and diseases. None of these are
easily resolved but the good news is people are trying and in the case of some species, such as Lepidium
banksii and L. rekohuense, they are so far staving o extinction.
Acknowledgements
When I started writing this article I received the tragic news that the ongoing COVID-19 outbreak
had caused the death of Art Whistler (1944‒2020) whom I had assisted with reviews of his threatened
plant surveys of Samoa, and in turn had learned so much of the ethnobotany of the Polynesian
peoples (Art’s life-long research passion). Art was convinced that Polynesians used and probably grew
Lepidium bidentatum, and fascinated about the etymological connections between the names nāu,
n’au and k’ao used for coastal lepidia in the eastern Pacic. I do hope people reading this are stimulated
to make a study of the subject. As for me, I have been fascinated by tales of Cook’s scurvy grass since
I was 10, and over the many years since then I have had the pleasure of working with a ra of people
on this fascinating plant and its allies. In particular, I would like to acknowledge the late David Given
and Bob Orndu for sharing their wisdom and interest in the plant and the ecosystem it inhabits. I
thank also David Norton of the School of Forestry, University of Canterbury, with whom I worked in
the 1990s, especially on New Zealand Lepidium and Jerry Cooper for taking a fresh interest in Albugo
and sorting out a little of the mess that awaits anyone dealing with that dicult genus. anks also
to Peter Heenan, Gary Houliston and Jeremy Rolfe for their help with the taxonomic revision of the
complex. While it would seem we are a long way o halting the decline of these amazing plants, there
is still hope this can be achieved.
References
Armstrong, T. 2007: Molecular detection and pathology of the oomycete Albugo candida (white rust) in threatened coastal
cresses. DOC Research and Development Series 274. Department of Conservation, Wellington.
Baker, S.D. 1955: e genus Albugo in New Zealand. Transactions of the Royal Society of New Zealand 82: 987‒993.
Beaglehole, J.C. 1962a: The Endeavour journal of Joseph Banks 1768-1771. Volume I. Trustees of the Public Library of New
South Wales, Sydney.
Figure 8. Albugo lepidii pustules on the rosette leaf of
Lepidium oligodontum (Point Somes, Waitangi West,
Rekohu / Wharekauri / Chatham Island). Photo: P.J.
de Lange.
11
Beaglehole, J.C. 1962b: e Endeavour journal of Joseph Banks 1768-1771. Volume II. Trustees of the Public Library of New
South Wales, Sydney.
Beaglehole, J.C. 1967: e journals of Captain James Cook on his voyages of discovery. III. e voyage of the Resolution and
Discovery 1776-1780. Parts 1 and 2. Hakluyt Society and Cambridge University Press, Cambridge.
Beaglehole, J.C. 1968: e journals of Captain James Cook on his voyages of discovery. I. e voyage of the Endeavour 1768-
1771. Hakluyt Society and Cambridge University Press, Cambridge.
Cheeseman, T.F. 1914: Illustrations of the New Zealand ora. Volume 1. Government Printer, Wellington.
Cheeseman, T.F. 1925: Manual of the New Zealand Flora. Second Edition. Government Printer, Wellington.
Dale, E.; de Lange, P.; Burns, B. 2017: Seed dispersal but not seed germination facilitated by seabirds: seed ecology of
Cook’s scurvy grass. New Zealand Journal of Ecology 41: 226‒233.
de Lange, P.J.; Norton, D.A. 1996: To what New Zealand plant does the vernacular “scurvy grass” refer? New Zealand
Journal of Botany 34: 417‒420.
de Lange, P.J.; Heenan, P.B.; Houliston, G.J.; Rolfe, J.R.; Mitchell, A.D. 2013: New Lepidium (Brassicaceae) from New
Zealand. PhytoKeys 24: 1‒147.
Esler, A.E. 1975: Vegetation of the sand country bordering the Waitakere Range, Auckland: Piha Beach. Proceedings of the
New Zealand Ecology Society 22: 52‒56.
Forster, G. 1777: Voyage round the world in His Britannic Majesties Sloop Resolution, commanded by Capt. James Cook,
during the years 1772, 3, 4 and 5. Elmsly and Robinson, London.
Gillham, M.E. 1956: Ecology of Pembrokeshire Islands. V. Manuring by the colonial seabirds and mammals with a note on
seed distribution by hulls. Journal of Ecology 44: 429‒454.
Gillham, M.E. 1960a: Plant communities of the Mokohinau Islands. Transactions of the Royal Society of New Zealand 88:
79‒98.
Gillham, M.E. 1960b: Vegetation of New Zealand Shag colonies. Transactions of the Royal Society of New Zealand 88:
363‒380.
Gillham, M.E. 1961: Alteration of the breeding habitat by sea-birds and seals in western Australia. Journal of Ecology 49:
289‒300.
Given, D.R. 1981: Rare and endangered plants of New Zealand. Reed, Wellington.
Hoare, M.E. (ed.) 1982: e ‘Resolution’ Journal of Johann Reinhold Forster 1772–1775. Vol. I–IV. Hakluyt Society, London.
Kirk, T. 1891: Descriptions of new plants from the vicinity of Port Nicholson. Transactions of the New Zealand Institute
24: 423‒425.
Kirk, T. 1899: e Students’ Flora of New Zealand and the Outlying Islands. Wellington, N.Z., Government Printer.
Moore, L.B.; Irwin, J.B. 1978: e Oxford book of New Zealand plants. Oxford University Press, New Zealand.
Norton, D.A.; de Lange, P.J. 1999: Coastal cresses (Nāu) recovery plan. Wellington, Department of Conservation.
Norton, D.A.; de Lange, P.J.; Given, D.R.; Garnock-Jones, P.J. 1997: e role of sea birds and seals in the survival of coastal
plants: lessons from New Zealand Lepidium (Brassicaceae). Biodiversity and Conservation 6: 765‒785.
Ogle, C.C. 1987: e retreat of Cook’s scurvy grass. Forest & Bird 18: 26.
Oliver, W.R.B. 1925: Vegetation of Poor Knights Islands. New Zealand Journal of Science and Technology 7: 376-384.
Orndu, R. 1960: An interpretation of the Senecio lautus complex in New Zealand. Transactions of the Royal Society of New
Zealand 88: 63‒77.
Orndu, R. 1965: Ornithocoprophilous endemisim in Pacic Basin angiosperms. Ecology 46: 864‒807.
Richards, E.C. 1956: Our New Zealand trees and owers. 3rd ed. Simpson & Williams, Christchurch.
Sparmann, A. 1780: Tres novae plantae, descriptae. Nova Acta Regiae Societatis Scientiarum Upsaliensis 3: 190-195.
ellung, A. 1906: Die Gattung Lepidium (L.) R. Br. Eine Monographische Studie. Basel.
Wilson, H.D. 1982: Stewart Island plants: eld guide. Field Guide Productions, Christchurch.
Wilson, C.M.; Given, D.R. 1989: reatened plants of New Zealand. DSIR, Wellington.
Funds available for possum control
e New Zealand Plant Conservation Network has the sum of $1,500.00 available for a possum control
project within New Zealand. is has arisen from a self-imposed Possum Tax levy on members of
the Australasian Systematic Botany Society (ASBS) during their attendance at the 2019 Joint ASBS-
NZPCN Conference in Wellington. e NZPCN has matched the amount raised by their Australian
counterparts and is now making these funds available for a suitable project within New Zealand.
e only criteria for applications for this funding are that the project must entail possum control and it
should ideally involve a threatened native plant species. Applications are now invited and should be sent
via email to info@nzpcn.org.nz. Final deadline for submission of applications is Tuesday 30 June 2020.
e successful application will be published in an upcoming issue of Trilepidea and a post-project
story will be published at a later date.
12
What value do you put on biodiversity (in a pandemic)?
e NZ Native Forest Restoration Trust
Even as the NZ Native Forest Restoration Trust were negotiating the purchase of Otatara sand dune
totara forest mentioned in last month’s Trilepidea, members of the Rotorua Botanical Society were
suggesting to Bay of Plenty Regional Council sta that they should ask the Trust for help to save a 14
hectare sand dune kanuka forest at ornton Beach west of Whakatane. Not just any patch of kānuka,
but the only 14 hectare patch in private ownership of Kunzea toelkenii. is species, described in 2014,
does not grow anywhere beyond the ornton beach front and a couple of nearby islands.
Current Conservation Status—2018: reatened – Nationally Critical
For detail on Kunzea toelkenii refer to http://www.nzpcn.org.nz/ora_details.aspx?ID=7642 or
de Lange, P.J. 2014: A revision of the New Zealand Kunzea ericoides (Myrtaceae) complex.
Quote from de Lange: “erefore, formal taxonomic
recognition is accorded here to any Kunzea entity
which demonstrates consistent morphological,
cytological, molecular and ecological partitioning
irrespective of whether it can or does hybridise,……
Ecologically, Kunzea toelkenii is further
distinguished as the only member of the K. ericoides
complex truly endemic to sand dune systems.”
While the Trust has NOT made a nal decision to
purchase the ornton beach property, we do see
the desperate need for it to be protected. To assist us
it would be helpful to have an indication of potential
support if we decide to buy. We hope you too can
see the future with the weird and wonderful Kunzea
toelkenii lining the beachfront at ornton.
We are asking the following questions:
• Would you be in a position to make a donation?
• If so what gure do you consider possible?
• Alternatively, could you advance a loan to the Trust at very low interest (or zero).
• We envisage a 2 to 5 year term. How much could you lend us, and for how long?
Alternatively, if you would like a beach front section in the Bay of Plenty, do contact us
e real estate advertisement is at https://nz.raywhite.com/whakatane-district/thornton/2236093/
You can contact us at admin@nznfrt.org.nz or view our website at www.nfrt.org.nz
If you would like to communicate with a Trustee, please email Geo Davidson at geo.bev.davidson@
gmail.com or phone him on 09 813 0229 or 021 764 967.
e contorted form of a typical ornton beach Kunzea
toelkenii. Starting life as prostrate shrubs, they form
dense thickets of foliage, developing numerous trunks
and opening into sprawling adults aer 30 years.
13
UPCOMING EVENTS
If you have events or news that you would like publicised via this newsletter please email the Network
(events@nzpcn.org.nz).
Please Note: It is strongly recommended that you contact your local Botanical Society to conrm
whether the advertised meetings and eld trips are proceeding as originally planned or whether
there are meetings or eld trips happening that are not advertised. e New Zealand Plant
Conservation Network accepts no responsibility for changes to the published details.
Auckland Botanical Society
Meetings and Field Trips: Cancelled until further notice.
Rotorua Botanical Society
Field Trip: Saturday 6 June to Matata sand dunes and coastal
lagoon. Meet: 8.00am at the Rotorua carpark or 9.00am at the
Matata campground carpark. Grade: Easy.
Leader: Sarah Beadel, email sarah.
beadel@wildlands.co.nz,
ph. 021 924 476.
Meeting: Monday 15 June at 6.00pm – AGM, followed by guest
speaker. Wine, juice, cheese and nibbles will be provided.
Venue: To be advised.
Wellington Botanical Society
Field Trips: Saturday 6 June. Postponed to 3 October.
Meeting: Monday 22 June (by Zoom only at this stage) – Speaker
Mark Alpine and others from the Greater Wellington Regional
Council. Topic: what’s happening in weed bio-control in the
Wellington region.
Venue (if meeting in person):
Lecture Theatre M101, ground
oor Murphy Building, west side of
Kelburn Parade.
Nelson Botanical Society
Field Trips: Cancelled until further notice.
Canterbury Botanical Society
Meetings: By Zoom or similar only at this stage.
Field Trips: Cancelled until further notice.
Botanical Society of Otago
Field Trips: Cancelled until further notice.
Meeting: Wednesday 10 June at 5.20pm – Speaker Dr Allison
Knight. Topic: Sexy Lichens.
Venue: Room 215, 2nd Floor,
Zoology Benham Building, 346
Great King Street.
