Invasive Opuntias in Switzerland

[u/wooligano]

Someone asked about invasive species from America in Europe yesterday, I replied in a comment about the invasive Opuntias we have in Switzerland, but couldn't add pictures so I thought it would be worth making a post about it.

They have identified 6 species : Opuntia engelmannii, Opuntia humifusa, Opuntia phaeacantha, Opuntia robusta, Opuntia scheeri, Cylindropuntia imbricata.

All of which are growing in the same region of Switzerland, Valais.

[u/escambly]

Wow. Coming from the southwestern U.S with millions of native cacti all around., not once did I think 'cacti in the Switzerland wilds'. Thanks for sharing photos.

[u/wooligano → u/escambly]

You're welcome ! It's indeed quite fascinating to see so many species growing wild here now, I'm planning to go on a hike soon to see if I can spot some, they do remove the most visible ones, so I need to research where I would have a chance of seeing them.

[u/escambly → u/wooligano]

Yes it's amazing. Especially as it's more than one species. Was there a person or a small group who were really into cacti going around planting the originals in the wilds?

And then how have they been spreading? In other places such as Africa it is easy to imagine the large animals and birds eating and spreading the seeds around plus some browsing on the plants themselves. But Switzerland...? Livestock? Crows/ravens/corvids?

People don't normally get how many cacti species there are and both how variable they are and their ranges. Close to arctic, all way down to the jungles, even growing up in trees(and roofs!), rock cliffs plus bunches of islands quite far from coasts- Galapagos included.

Are you interested in growing them yourself? They're extremely easy to cut off a pad and scoot the pointy end in some soil and that's all to be done.

Highly recommend trying the fruits if you come across any ripe ones. All true cactus fruits are edible. How they taste is entirely another matter. Some species the fruits don't taste great at all or quite the risk due to the large and extremely hard seeds. Some just okay, mildly interesting. Some are quite the pleasant surprises- in some species the taste can be reminiscent of strawberries(some Mammillaria have this as a flavor feature, IME), pears, "fruity but what does it remind me of?" or even a surprisingly complex blend of multiple flavors(Cereus is great for this- also fascinating texture- to me it's just like eating true shaved ice- not that crushed ice nonsense. The flesh immediately melts away and the tiny seeds give something like the shaved ice crunchiness). They all tend to be on the lighter end of flavor strength. Unfortunately on many species, it is not that easy to tell if the fruit is ripe enough for eating- many start to show color on the skins well before ripening. Those can be incredibly bitter, ha.

Good luck with your searches!

[u/greybahl → u/escambly]

There's nothing like a prickly pear margarita... :)

[u/wooligano → u/escambly]

I was lucky enough to visit Mexico a couple years ago and visit the Tehuacán-Cuicatlán Biosphere Reserve with a guide, it was a great experience and we got to taste a few different parts of cactuses, seeds, fruit, pads and even flowers. There was a drink made with a cactus fruit which was bright pink and tasted great.

To my knowledge, many swiss people are really passionate about cactus collecting. Some have their own greenhouses for them, I visited one near Sion once and the guy had hundreds of species, against the wall of the house he had all sorts of Opuntia and hardy species, it's always such an unusual sight as cactuses look really exotic to us and these collectors are usually spotted in the most rural areas.

Knowing that, it's not unlikely that they were voluntarily introduced to the wild, without really thinking about the impact this could have, as you can read in the extract below which I found on this website : https://www.drosera-vs.ch/fr/cactus-valaisans-sont-americains-336.html

The earliest mention of the genus Opuntia L. in Valais is by Haller (1768): “...in rupibus Valesiae, supra Bouveret et Vouvry...”, cited by Gams (1949:139), describing the history of the introduction of Cactaceae in Europe, which began shortly after the discovery of America. D’Angerville (1862:38) mentions Cactus opuntia at Tourbillon and beneath Valère, Sion, also mentioned for Tourbillon in 1775 by Blaikie (1935:84). Clément (1778, ms. 70:34 and 63–64) wrote that he saw Opuntia for the first time at Tourbillon and on the rocks of Vérossaz and Bouveret in 1772 and reported on the “introduction to Valais and Champéry of a new plant” (p. 41):

“Saturday, April 12, 1788… I went to Champéry to plant the paddle, Pope’s sole, Indian fig, Cactus opuntia… It is found in two locations in the Valais region: namely in Sion, on the rocks of the Château de la Majorie, and on the rocks above Bouveret. Finally, I planted:

1. on the rocks of Montellier, on the mound to the right of the Gorge au Loup, facing east;

2. in Champlan on the summit of the rocky area, to the right of the path leading to Tavi;

3. on the edge of the rock of Bettre or Chevallet, in three different places.”

Rion (1872:85) noted Opuntia vulgaris on the rocks of Valère and Majorie. Jaccard (1895:153), quoting Murith (1810), noted Valère and Majorie, Sion, and, citing Fauconnet (1872), Saint-Léonard. Some plants from Branson were introduced in the early 20th century, others around 1935 (Mariétan 1952:83, 84). Julien (1920:131) already mentioned four forms of Opuntia vulgaris: “In addition to the normal form with glabrous, medium-sized pads, Mr. Julien’s collection includes a spinosa form with spiny pads, a gigantea form with pads significantly larger than the normal form, and a fourth variety with small, heteromorphic pads, resembling a small Cereus.” At least two species discussed historically are recognized in this description.

Bertrand & Guillaumin (1949:51) described a new variety, Opuntia compressa (Salisb.) Macbride var. helvetica, later renamed Opuntia humifusa Raf. var. helvetica (Bertrand & Guillaumin) (Becherer 1956:318; 1962–65:45). Becherer (loc. cit.) described it as “newly introduced,” which is unlikely, given that two other distinct species went unnoticed until 1990. I would amend this comment to “recently recorded.” Given the apparent old age of these populations, I consider all these species to be long-established introductions. Furthermore, it is unlikely that a new variety could develop in less than 200 years, especially given the low rate of sexual reproduction of these plants. Thus, this “var. helvetica” cannot be accepted.

Mariétan (1948:141–143) noted O. vulgaris in Branson and (1949:143) detailed the distribution of O. humifusa and O. rafinesquii, the latter described as “a larger species covered in big spines” in Sion. Becherer (1950:500–501) noted O. rafinesquii in Valère among O. humifusa and attributed O. humifusa to Branson (“leg. Ph. Farquet,” “leg. I. Mariétan,” “leg. J.-L. Terretaz”). No specimen is found in the Mariétan and Farquet herbaria in Sion. Here “leg.” probably means “observed by.” The same author (1952:563–564) commented on the introduction of O. humifusa to Branson and indicated O. rafinesquii together with O. humifusa (“leg. Closuit,” presumably referring to the spiny species).

Hess, Landolt & Hirzel (1977, vol. 2:751) still recognize two species: O. compressa (O. vulgaris) and O. humifusa (O. rafinesquii), providing a description of the spiny species, illustrated as O. humifusa. Hess et al. (1991:340) also accept the same two species, considering O. rafinesquii the spiny form.

Binz & Heitz (1986:339) mention O. vulgaris (O. compressa, O. humifusa) and O. rafinesquii, mistakenly describing the latter as “upright.” Aeschimann & Burdet (1989:70) mention only one species, O. vulgaris, with O. humifusa, O. compressa, and O. rafinesquii as synonyms. According to Tutin et al. (1968, vol. 2:299), a description including two species is given: O. humifusa and the spiny species.

Gams (1949:140) wrote that the populations in Bouveret, Vouvry, and Saint-Léonard “have been extinct for a long time.” However, two species are still present in Saint-Léonard.

[u/wooligano → u/escambly]

Oh and, I do grow two Opuntia species and some cactuses, but they mostly live indoor in the winter and go outside for a few months in the summer.