Eduart Zimer - (SDU) - Adventive Plants - Part 5 (2008)

download Eduart Zimer - (SDU) - Adventive Plants - Part 5 (2008)

of 18

description

Part Five of "Succulent plants from down under – Adventive Plants".

Transcript of Eduart Zimer - (SDU) - Adventive Plants - Part 5 (2008)

  • Page 1

    Succulent plants from down under Adventive Plants (Part 5):

    Cakile maritima ssp. maritima - Aloe maculata - Opuntia monacantha

    XI. Cakile maritima ssp. maritima

    I have to admit that Cakile maritima Scopoli 1772 ssp. maritima was kind of mystery plant for me for few months, after I have noticed it on some Coromandel Peninsula beaches like the legendary Opoutere beach and Whangamata beach, growing along with native sand dunes grasses or alien succulent plants. My first thought was that it has to be a native plant and I was looking for months unfortunately in this direction, but not getting even a clue of what it might be. I even have in Part 3 of this series o photo showing Carpobrotus edulis growing amongst native succulent plants that native succulent was Cakile maritima (1). One day I posted a short message and links to some photos on Didge Rowes Xerophytes NZ notice board and I finally got the answer someone new in an instant whats all about.

    1. Cakile maritime ssp. maritima growing with Carpobrotus edulis at Whangamata, Coromandel. By the time this photo was taken I was pretty sure that this must be a native plant.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 2

    There are quite a few things worth knowing about this plant, dull and insignificant at first sight, but full of surprises on a closer look. First of all the well known Searocket by its vernacular name is a highly resistant halophyte plant; it takes it to the extreme being able to survive concentrations of over 400mM of NaCl (salt). I have briefly mentioned in a previous article (2) how halophyte plants manage to survive killer concentrations of salt, but Cakile maritima is somehow different from Sarcocornia quinqueflora. By being annual plants (3), with fruits ripen in summer shortly after the flowering period, and seeds germinating in winter, the seeds are therefore very tolerant to higher salt concentrations, like most of the annual halophytes. Not all seeds are germinating at the same time; this would be very risky and unwise in adverse environments as the fore dunes usually are - some of them form long lasting seed banks ensuring a constant germination over a period of time, ensuring new generations no matter what, if by some extreme conditions entire populations or seedlings became extinct. It is this asynchronous germination of most annuals in hazardous environments that maintain the continuity of the species. As expected the seeds have also a high longevity, it maintains for three years a high germination rate, being able to germinate on occasion even after many years. Seed banks are very resistant to soil disturbances even if these occur several times a year for two or three years in a row and this may happen in very unsettled sand dunes habitats. This is actually the preferred habitat, not the wet. It is very resistant to salt spray and transient sea water inundation; capsules are floating on sea water and retain the germination capability of the seeds, although these are reluctant to germinate in extremely high salinity environments dispersal by sea (waves, currents, winds) seem to be a very efficient vector.

    Although beach and dune sand is (beside its high salt content) a very poor substrate, with barely any nutrients with nitrogen content, Cakile maritima has a very positive reaction to local and / or casual nitrogen enrichment showing explosive growth and vegetative development, unlike most of the typical plants sharing this habitat (like Spiniflex spp., Calystegia spp., Disphyma spp., Carpobrotus spp., etc. showing poor growth or simply avoiding such areas), especially in association with mineralization. Growth is also highly stimulated by perturbation events like persistent strong winds, burial by blown sand, temporary sea water inundation, various soil disturbances, etc., drifting plants or plant parts removed from their original locations being able to form extremely quickly the nuclei of early succession fore dunes vegetation elsewhere.

    2. Cakile maritima ssp. maritima tussocks scattered on the beach at Whangamata.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 3

    Cakile maritima ssp. maritima (belonging to Brassicaceae, the mustard family), is a low growing bushy plant, with stems reaching only 10 30 cm, much branching from the base, stout and glabrous, from sub-erect to decumbent, spreading and forming small mounds, usually 30 x 30 cm. Both stems and leaves are succulent. The fleshy leaves form a very loose rosette and are narrow-oblong to ovate, shallowly to deeply crenate, petiolate, 40 60 mm x 10 20 mm, with leaf margins usually entire but on occasion shallowly crenate or sinuate. Stem leaves are usually much smaller, crenate, and usually having a different shape from oblong to linear to linear-spathulate. The four petal flowers are hermaphrodite have 10 mm diameter and are whitish to pale lilac, growing in loose clusters on 1 3 mm long and spreading pedicels, and pollinated by bees, flies, beetles and moths. The inflorescence is straight, thickening and elongating at fruiting. As the specific epithet shows the plant is fully confined to maritime strandlines growing usually on sand and shingle and on the nearby fore dunes. Cakile maritima is found around the shores of Western and Southern Europe and North Africa, several subspecies are known showing significant differences in fruit morphology and leaf form (4). Another closely related species - Cakile edentula is native to the east coast of North America. Both species have been introduced on the Pacific coast of North America in some of the Pacific Islands, Australia and New Zealand posing a moderate threat to native coastal flora. The primary danger is not the direct

    3. Cakile maritima ssp. maritima at Whangamata.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 4

    competition with native plants for resources, Cakile maritima is rather a pioneer plant, establishing quickly in disturbed habitats, but not performing too well in dense vegetation areas; it has been established that the plants from scarcely vegetated beaches are the main seed source for new plants in grassy former fore dunes, the germination rate is so poor in such areas that an external seed flux is really necessary to maintain the populations on the long run. It is therefore less effective and less threatening in my opinion for the New Zealand coastal ecosystems than you might be considering in first instance. As in its original habitat the importance of Cakile maritima in the conservation of the coastal habitats has been acknowledged, I think that being a first succession pioneer plant, by dominating the drift vegetation type and giving up in established environments, it is acceptable for New Zealand for conservation purposes in highly degraded and volatile coastal ecosystems. It is apparently more of a dune initiating plant, rather than dune building, and therefore preparing the environment for the secondary successions. Cakile maritima has usually a higher salt tolerance than the secondary succession plants.

    It is very interesting that the genus Cakile has a huge dispersal, an almost worldwide range. It is considered that an ancestral Cakile sp. was originally a desert plant, being probably similar in habit to Cakile arabica. From some reason this ancestral Cakile made the transition from a desert to a maritime

    4. Cakile maritima ssp. maritima at Opoutere, Coromandel.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 5

    habitat and experienced a consequent increase in global range by using the waterways for medium and long-range dispersal. As the salty seawater does not damage the floating capsules of the plant or the seeds themselves for quite a time it might be a reasonable explanation (5). To complete its profile even if a warmth and sun loving plant (does not grow in shade at all) it is also frost hardy during winter, surprisingly for a coastal plant, possibly due to recessive genes inherited from the ancestral desert Cakile.

    Very surprisingly the plant used to be cultivated in Great Britain not only for its aspect (very interesting indeed, but not really showy for my taste) but also for culinary uses; rich in Vitamin C but very bitter, the plant (pretty much everything leaves, stems, flower buds and immature seedpods) was used mainly as a flavouring spice, raw or cooked.

    The plant is quite wide spread in New Zealand (it has been naturalized in 1940), but only in the North Island: Kaitaia, Bay of Islands, Hukerenui (Northland), Whangapararoa (Auckland), Thames, Opoutere,

    5. Although both are beaches with eastern to northeastern exposure at the Pacific Ocean, the Opoutere plants have a somewhat different look, smaller sized, showing clearly the pressure of a very harsh environment. In contrast, the Whangamata plants have that peaceful nice look of cultivated plants. This plant was photographed at Opoutere.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 6

    Whangamata (Coromandel Peninsula), Bay of Plenty, East Cape, Gisborne, Hawke's Bay; Waipawa, New Plymouth, and Wellington. I have seen the plant in two of the locations mentioned in Flora of New Zealand, Vol. 4 Opoutere and Whangamata (Coromandel Peninsula), abundantly but never causing high-density infestations, on sandy beaches close to the high tide line.

    XII. Aloe maculata

    I have already briefly mentioned Aloe maculata (Aiton) Haworth 1804 (usually referred as Aloe saponaria (Aiton) Haworth 1804 by New Zealand botanists) in relation with the succulent plants of Rangitoto Island, Hauraki Gulf, but I think that going a bit into details will have some relevance as this

    6. 8. Taking a picture of Cakile maritima ssp. maritima at Opoutere (above left) and habitat pictures at Opoutere (above rightand left).

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 7

    plant even if extremely common and very adequate for beginners seem to be everyones favourite and often encountered even in fancy collections.

    It is usually quite tricky to identify the spotted Aloe plants, some of them extremely similar when not in flower, but Aloe maculata is fairly distinctive (6). It forms clumps of stemless (or forming in time a very short stem) succulent rosettes usually to 25 30 cm high (on occasion up to 50 cm high) and 25 - 30 cm wide (on occasion 40 50 cm wide). The succulent leaves usually 12 20 in a rosette may vary in shape (7) but are usually elongated triangular broader at the base and getting thinner toward the tips; in some plants the leaves may have an almost belt-like appearance. The green leaves are copiously spotted with whitish to light green spots on the upper surface, arranged in vaguely transversal stripes, more or less evident, sometimes in wavy designs. Sharp brownish marginal teeth are present. The upper side of the leaves is usually plane to slightly concave while the lower side is in most of the plants spotless and convex. The plant is very prolific in sending rhizomes in all directions to shoot new plantlets eventually forming large clumps. The axillary inflorescence is branched and bears usually red to red-orange flowers, but there are also salmon-red, orange and yellow flowering forms, and of course all possible

    9. Aloe maculata, young plants growing directly on lava block on Rangitoto Island, Hauraki Gulf. Collected debris seems to be the only moisture retainer.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 8

    nuances in-between. Aloe maculata appears to have (at least this is my experience) a limited self-compatibility on occasion otherwise it is self-sterile.

    Aloe maculata has a wide distribution in South Africa (reaching from the Cape Peninsula to the Western and Eastern Cape Provinces through Orange Free State and KwaZulu-Natal and Mpumalanga), Lesotho and Zimbabwe in a variety of habitats from grassland to thicket and rocky outcrops. It occurs mostly in milder coastal climates, with humid winters, but also deep into the inland at higher altitudes and in summer rain areas. Having such a wide dispersal area it is not threatened at all, but present in large numbers in numerous locations.

    10. This is the main rosette of the plantlet collectedfrom Wenderholm in July 2003. Although I have tried to grow it hardy and in full sun there is nothing like a wild plant.

    11. Typical inflorescence of Aloe maculata the flat raceme.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 9

    Aloe maculata is definitely a very successful plant, not only for being a favourite landscaping plant, but also for becoming if not naturalized then at least a casual and persistent presence, a typical garden escape, basically in all tropical and subtropical regions of the world, especially in the Mediterranean region, India, China, Australia, New Zealand, some of the Pacific Islands, United States (especially in the south-west where numerous escapes have been observed) and even South America.

    This plant is extremely popular here in New Zealand to begin with, probably the most cultivated Aloe. The easy-going nature of this plant and the beautiful foliage and flowers contributed to its early success in gardens, escaping probably very soon in nature. The first New Zealand collection is dated 1883 (one of the first succulent plants naturalized here) and was made by T. F. Cheeseman in Remuera (Auckland), identified as Aloe latifolia (Haworth) Haworth 1804, now considered to be a synonym.

    Aloe maculata is quite widespread here in New Zealand being one of the very few fully naturalized

    succulent plants (opposed to adventive or casual appearances) and there is no wonder that it managed to do this, as it is very popular in cultivation. It is a therefore typical garden escape, discarded garden waste

    12. Aloe maculata a wild beauty from Rangitoto Island, Hauraki Gulf.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 10

    being probably the most likely mean of dispersal. But unlike other escapes this plant has really managed to form self-maintained populations occurring in several sites throughout New Zealand. The plant is usually referred as Aloe saponaria (Aiton) Haworth 1804 by most New Zealand authors and although the name is incorrect it looks like this tradition is hard to break.

    Few significant wild populations have managed to establish in time mainly in the northern half of the North Island - such as Mt Puheke in Karikari Peninsula and Tokerau Beach - Paihia (Northland), Auckland City, Rangitoto Island (Hauraki Gulf) but also few South Island populations are scattered on the coastal areas of Canterbury and Christchurch; as you can see it is confined to coastal areas.

    I have seen this plant in nature in two different locations. The first time in July 2003 at Wenderholm, 40 km north of Auckland, in a Regional Park (which is actually a mixture of recreational area and nature reserve) in a vegetation control area, at 100 m or so far from the waterline, in a light wood area. There was a nice clump of several dozens of rosettes, some bigger mature plants, some just few centimeters wide plantlets, forming a semi-circular colony around the base of a big tree. It had some sun there, but

    13. Same plant as above. In Rangitoto I have seen just isolated loose groups of plants, few dead ones too, scattered from place to place on the eastern shore, but not large clumps as in Wenderholm.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 11

    probably mostly placed in shade, the plants looked more like cultivated plants, very nice however. It was a small but well settled population. I took a small rosette, a plantlet of ca. 5 cm diameter, which became the starting point of vegetative reproduction in my greenhouse and rock garden, giving away some other clones as well. Unfortunately I didnt manage to take pictures of this nice clump (I didnt have a digital camera at that time), and one year later I was surprised to see that this lovely group of plants has been destroyed and replaced with native vegetation, most likely the normal outcome for any intruder in a controlled vegetation area. They must have done a pretty good job, as I havent seen re-growth of the Aloe maculata since.

    The second location is Rangitoto Island (Hauraki Gulf), where I have seen few sensational plants during my second trip there in January 2008. I wrote about the Rangitoto plants in Part 4 of this series; these are the plants that have impressed me most, truly wild plants growing on bare lava fields covered with lichens, having mostly debris around them as moisture retainers, just few of them finding shallow rocky substrate but no organic matter at all. All plants were displaying the brownish signs of stress inducted possibly by lack of water or excessive sun exposure, or by both - these were probably the most beautiful

    14. The young plantlets from Rangitoto seem to be according to the red-brown colours displayed quite stressed by the scarcity of the water, or by the intense sun exposure, or by both, but this is life in the wild.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 12

    succulent plants I have seen in the wild. These plants have, I like to underline this, real character. Not fancy chaps, but true survivors.

    XIII. Opuntia monacantha

    Opuntia monacantha Haworth 1819 is probably the most common opuntioid, everyone seem to know it,

    have seen or had one, and so on. There is nothing special about this plant, widespread and almost a pest even in its own habitat, but definitely there was a pleasant surprise for me as I saw it in nature (by pure chance) on a sunny day spent with my family at Eastern Beach, Howick, Auckland.

    No surprise for a very common cactus there is some confusion around it. Adrian Haworth described the species in 1812, in Synopsis Plantarum Succulentorum. Haworth based his description on a plant from Barbados, outside the natural distribution area. It is known today that it was introduced there and that the only native Opuntia is Opuntia dillenii. He also refers also (with a question mark) Cactus monacanthos Willdenow 1814 as synonym, but this indication of doubt makes under the current rules impossible to consider Willdenows a basionym for that of Haworth, and therefore the quite often cited name Opuntia monacantha (Willdenow) Haworth 1819 is not correct. Also the name Opuntia vulgaris of different authors, including Miller, has been misapplied quite often by Australian and New Zealand authors; due to this confusion in early New Zealand botanical records the plant is referred as Opuntia ficus-indica, the source of a chain of confusion for many decades. Opuntia vulgaris Miller has now been typified to become a synonym of Opuntia ficus-indica (Linnaeus) Miller.

    The plant has usually a tree-like appearance, being usually 1.3 4.0 m tall, on occasion even more, and having a terete trunk; in some plants this trunk is absent, the plants having then a rather shrubby appearance. The pads are glossy green, obovate to oblong, narrowed at the base, usually 10 30 cm long

    15. Opuntia monacantha, the bigger plant seen at Eastern Beach, Howick, Auckland. It grows on almost vertical cliffs between grassy patches. From place to place organic matter seems to have been accumulated in the cracks, some moisture is available as well from the ground water.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 13

    and 7.5 12.5 cm wide, with large areoles of 3 5 mm diameter and bear brownish 2 3 mm long glochides. The spines are quite sparse on the joints, usually 1 or 2 per areole, sometimes 3 or even absent, but densely on the main trunk up to 12 per areole. The spines are erect or spreading, usually grayish with dark brown tips. The leaves are conic and 2 4 mm long, deciduous, not lasting too long. The flowers have 5.0 7.5 mm diameter, the sepals being yellow with reddish midrib, while the petals usually yellow, sometimes to orange. The fruit is obovoid with slightly depressed umbilicus and bears light tan irregularly elliptic seeds of 3 4 mm. It usually flowers from mid spring to mid summer provided strong sun and heat is present.

    Opuntia monacantha is native to Argentina, Brazil, Paraguay and Uruguay, but has been widely introduced and naturalized in almost all tropical and subtropical regions, from Florida to tropical Africa, to South Africa, southeast Asia, Australia, New Zealand and some of the Pacific Islands, and I think there must be some other places too. The worst infestations have occurred in Australia and South Africa. It is also worthwhile mentioning that Opuntia monacantha was first recorded in China as early as 1625.

    16. This is the smaller plant growing almost hidden by grasses some 1.0 1.5 above the bigger plant.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 14

    Opuntia monacantha (usually referred as Opuntia vulgaris by New Zealand authors, unfortunately a compromised name, often misapplied to Opuntia ficus-indica) is nowadays not too wide spread here in New Zealand in nature and this is quite a surprise considering the high occurrence in the past and the Australian disastrous Opuntia introductions (8). However, it is the only fully naturalized Cactaceae in New Zealand. Very popular in cultivation at some stage, Opuntia monacantha has managed to escape in nature the most likely infestations being from abandoned plantations and dumped garden waste. At some stage I think this was the fate of many garden plants going out of fashion and in older times no-one put too much thought in how to discard the garden waste. I was told that the sand dunes of Mt. Maunganui were a preferred place for such organic dumps for locals and few decades ago you had to consider very wisely walking barefooted through the area as rooted Opuntia pads were littering the place. Reportedly none has survived, but youll never know for sure unless you go there and browse thoroughly the area (9). This fierce and invasive aggressor (considering the disastrous Australian events) has barely managed to naturalize in New Zealand.

    I think there is enough potential for isolated plants or small groups of plants to survive for extended periods though. Opuntia monacantha can be on occasion very prolific in vegetative dispersal as pads fallen on the ground root easily; also seed dispersal has been observed which is even worse. It just

    17. Close up a pad from the bigger plant and the remainders of a flower.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 15

    doesnt seem to be very effective in dense vegetation areas. It prefers warm and sunny banks and slopes, sand dunes, beaches and rocky outcrops where it can form small self-maintaining populations, but it also occurs in somewhat cooler locations. It is quite tolerant to marine exposure and also to moderate salt concentrations. The New Zealand botanical literature refers following populations: Hokianga Harbour and Mangonui (Auckland), Bay View - Napier (Hawkes Bay) (10), Awato (Nelson), Teviotdale Station, Conway Flat, Waipara and near Waipara on the road to Weka Pass (Canterbury), Halswell Quarry (Christchurch) (11) and - with a single known collection - Lowburn (Central Otago), which is the only truly inland location, all others being coastal or near-coastal populations.

    I have seen Opuntia monacantha in just one location Eastern Beach (Howick, Auckland), a location which is not mentioned anywhere else so far I know, on the cliffs at the southern end of the beach, between grassy patches. Unfortunately I didnt have the binoculars with me that day so that I couldnt scan thoroughly the area. The two plants, hanging on almost vertical cliffs with eastern aspect were probably at 3 4 m above the high tide mark, in a place, which can be accessed only at low tide. It could have been more of them but I couldnt see them. As on the plateau, some 25 30 m above, there is a residential area and many decades back, when Howick used to be well outside the settled Auckland urban area, holiday baches were scattered, it looks like these plants are also remainders of dumped garden waste. Looking at the residential properties above and the associated modern landscaping designs this must have been the case. I think that I am not too far off maintaining that someone simply uprooted and threw down the slope that big ugly cactus while builders were busy with the setup of the new swimming pool. On the northern slope of the cliffs, exactly where the beach begins, in a more densely vegetated area, there is also one of the most extensive Tropaeolum majus infestations I have seen in New Zealand.

    18. Eastern Beach, Howick, Auckland the steep where I saw the two Opuntia monacantha plants.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 16

    I have seen just two plants, a mature plant having already flowered and, just 1 1.5 m above, a much younger plant. This is rather strange that the much younger plant is placed above the older one. It is virtually impossible to originate from a pad removed from the plant below and lifted somehow up by strong wing, or even from seed dispersed upwards, there must have been some other plants higher on the cliff, possibly hidden between grasses and shrubs, which I couldnt see. This younger plant originates probably from seeds or pads dispersed from other plants above. I also discard a continuing source of infestation form the plateau, this is highly unlikely.

    I will probably return at some stage at Eastern Beach (making sure that I have the binoculars with me this time) and I am pretty confident that new plants will be sighted. However, the unexpected finding of these quasi-wild growing cacti was enjoyable enough.

    19. From place to place you can see moist patches due to the water sipping between the sediment layers from the ground water.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 17

    Additional References:

    A. G. Davy & al. - Biological flora of the British Isles: Cakile maritima Scop (Journal of Ecology, Vol. 94, 2006);

    Flora of China (http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242423528);

    John J. Knapp, Joseph M. DiTomaso & al. Cakile maritima Scop. Plant assessment Form electronic version February 2003 (for the California Exotic Pest Plant Council and the Southwest Vegetation Management Association);

    Wided Megdice & al. Salt tolerance of the annual halophyte Cakile maritima as affected by the provenance and the development stage. (Acta Physiol. Plant., vol. 29, 2007 published online by the Polish Academy of Sciences, Krakow 2007);

    Bridget Ozanne & Charles David - Interesting Plants of Guernsey (not dated), http://www.guernsey.net/~cdavid/botany/files/plants.html;

    Plants for a Future - http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Cakile+maritima;

    Ben-Erik van Wyk & Gideon Smith - Guide to the Aloes of South Africa (1996);

    E. Zimer Aloe maculata (www.cactusi.com Cactus Romania Enciclopedie, 2006).

    Further Readings:

    R.W.G. Carter & Bill Carter - Coastal Environments An Introduction to the Physical, Ecological and Cultural Systems of Coastlines (1988);

    John R. Packham, Arthur John Willis Ecology of Dunes, Salt Marsh and Shingle (1997);

    My Notes:

    (1)

    I will keep this error, as this series is not only an account on the naturalization of alien succulent plants in New Zealand, but also accounts for my personal evolution on the matter. I have also omitted to mention this plant in my 2007 Romanian article Plante suculente narturalizate in Noua Zeelanda published on Aztekiums website thinking in error that it has to be a native succulent.

    (2) Succulent plants from down under Sarcocornia quinqueflora an odd succulent halophyte (2007).

    (3) Referred usually by botanic authors as an annual plant, reportedly in some situations it may have a biannual or even short-lived perennial habit, with some shoots remaining leafy during winter. Such bizarre alterations of the habit have been seen in another halophyte plant naturalized in New Zealand Salicornia europea. John J. Knapp, Joseph M. DiTomaso & al. (2003) are the only botanical authors I have read who consider the plant as being biannual, Flora of New Zealand Vol. 4 mentions only the leafy shoots remaining during winter.

    (4) I wont enter into taxonomic details; I will only mention that the well-known Cakile maritima ssp. integrifolia often mentioned in British botanical records is actually a synonym of Cakile maritima ssp. maritima.

    (5) The late Dr. Phil Maxwell (the author of The Rhipsalis Riddle - or the day the cacti came down from the trees, 1998 I highly recommend this article) was a very fierce critic of the easy-explanation long range dispersal vectors (birds, sea currents, land-bridges connecting everything between actual continents to mythic land-masses, etc.) usually advocated when no obvious reason is available and I totally agree with him. However, it was proved that Cakile maritima is able to be dispersed on very short distances by the joint action of tides and coastal currents and therefore I cannot rule out completely in this case this dispersal vector even on longer distances.

    (6) You cant miss it when in flower the flat top of the racemes is characteristic for the species.

    (7) It was due mainly to the leaf form and design that we have many names and synonyms given to his plant, mainly in the 18th and 19th centuries. There are four different factors though a natural variability of the leaf form, spots arrangement and colour, flower colour and (very visible in cultivated plants) the intensity and duration of the sun exposure allowing for different looks.

    (8) I hope that I will be able to write some time next year about the Opuntia plants of Australia, their invasive behaviour and the surprising lack of success in New Zealand.

    (9) On Didge Rowes Xerophytes NZ notice board David Kirk of Tauranga wrote: As a kid I remember a monacantha 'tree' growing next to a right-of-way at Mt. Maunganui, a massive spiky trunk and all... I wonder if it's still there? Walking in the sand dunes was sometimes relatively perilous, as the dunes were a favorite dumping-ground for garden waste and small bushes of the Opuntia were established in the undergrowth. They've all gone now, but there remains an interesting mixture of old-fashioned bulbs I've never seen elsewhere (apart from two Lachenalia sp); at least three unknown Gladiolus species, etc., and the commonly-encountered Cotyledon orbiculata v. orbiculata (?), anyway, the silver-grey one.

    (10) Well established on sand dunes and growing amongst Opuntia ficus-indica, Lupinus arboreus and Ammophila arenaria.

    (11) Growing on rock rubble with Opuntia robusta, Sedum dasyphyllum and Ornithogalum longebracteatum.

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com

  • Page 18

    ------------------------------------------------

    All errors, omissions and misconceptions are mine.

    All photos by Eduart Zimer, except 6 by Dan Georgescu.

    Eduart Zimer, September - October 2008

    http://eduart.page.tl/Home.htm

    PDF Created with deskPDF PDF Writer - Trial :: http://www.docudesk.com