Showing posts with label Obregonia. Show all posts
Showing posts with label Obregonia. Show all posts

Sunday, April 11, 2010

The killing frost – casualties and survivors

First a bit of background information so that you guys won’t believe that I am completely stupid growing Lophophora and the likes in an unheated greenhouse in Denmark: 1) Most of these plants are “surplus”, i.e. I don’t have room for them anywhere else – lately several plants have been bought specifically for the cold house, though. 2) The greenhouse is located at my summerhouse, left mostly desolate throughout winter, making it difficult to keep it reliably heated. 3) Many cactus species tolerate more frost than is generally assumed; I’m curious which. 4) The winters in Denmark have been rather mild lately, inviting experiments like this.

With this in place I’m ready to recount how the harsh winter, that has just released its cold grip of Denmark, helped me separate the wheat from the chaff (a blatant euphemism for “killing off alarmingly large parts of my collection”). Just to give an understanding of the severity of the winter, the plants saw almost constant frost for more than 10 weeks, with temperatures measured as low as -15 C (5 F) in the area where the plants grow.

Lophophora williamsii var. echinata coming out of winter
Lophophora williamsii var. echinata coming out of winter

Let’s start with one of the success stories. My Trans-Pecos peyote plants are doing quite well, approximately one in eight died and the surviving plants are not too marked by the frost. The plants I'm growing are descending from material originally collected in the Pecos River area, Val Verde County, Texas (JJH 8608293). The Trans-Pecos peyote is the northernmost form of Lophophora williamsii and is also known as Lophophora williamsii var. echinata.

Trans-Pecos peyote surviving the frost
Trans-Pecos peyote surviving the frost

My regular (Mexican and south Texan) Lophophora williamsii plants fared much worse, less than one in ten of the larger plants survived the winter.

One of the few surviving Lophophora williamsii var. williamsii
One of the few surviving Lophophora williamsii var. williamsii

This corresponds well with Del Weniger’s observations:

[Lophophora williamsii var. echinata] can also survive the much more severe cold of the Big Bend. I have several times had the smaller form from south Texas [L. williamsii var. williamsii] freeze in San Antonio, while this form [L. williamsii var. echinata] growing in the same bed showed no ill effects.

In the future I'll focus more on the extreme northern forms of peyote, i.e. plants grown from material originating from Shafter, Val Verde, Big Bend and other Trans-Pecos, Texas locations. The Cactus Conservation Institute has an informative page on the differences in traits between Lophophora williamsii var. echinata and var. williamsii.

Frost killed Lophophora williamsii, Starr County, Texas
Frost killed Lophophora williamsii, Starr County, Texas

As mentioned the majority of my large “regular” Lophophora williamsii were killed by the frost. But many medium sized seedling plants actually survived while the larger plants (of the same variety) and yearling seedlings succumbed. As this pattern seems to be rather consistent for plants of the same variety, I guess I can’t write all “regular” Lophophora williamsii casualties off to genetics. My theory is that this “size-conditioned” difference in survival must be related to how well the plants were prepared for the winter, which again may be closely related to the surface-area-to-volume ratio of the plant.

The surface-area-to-volume ratio (SA:V) decreases with size, i.e. a large plant will have less surface per unit of volume than a smaller plant. If we use a half sphere as a model for a globular cactus we get a SA:V of 3/r, where r is the radius. Consequently a large plant will need relatively longer time (per unit of volume) to go flaccid and prepare properly for the winter (as all excess water needs to be evaporated through the surface (the epidermis)). Similarly seedlings are more prone to die of drought as an increased SA:V means increased exposure to the environment in general.

To play it safe the coming growing seasons I'll stop watering my large plants well before I let seedlings go drought dormant in preparation for the winter, and in general start winter preparations earlier than I have used to in the past.

I might consider crossing the surviving mature (non Trans-Pecos) plants and name the cultivar Lophophora williamsii 'Borealis' ;-)

Frost killed Leuchtenbergia principis – outside the rain is weeping
Frost killed Leuchtenbergia principis – outside the rain is weeping

My largest Leuchtenbergia principis is dead (pictured above next to a surviving saguaro) while 3 out of 4 of my smaller Leuchtenbergia principis plants (GL 770; Sierra de la Paila) are looking happy.

Ariocarpus has turned out to be an unconditional coldhouse success. I expected my Ariocarpus fissuratus plants to make it safely through the winter as they originate from locations like Fort Stockton, Texas (JM 122) and Crockett County, Texas (SB 403), but I had doubts about my Ariocarpus kotschoubeyanus var. macdowellii plants (SB 100; El Pilar, Coahuila), and had accepted that I would probably loose my Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila). Amazingly they all survived the winter in great style almost looking lush and vigorous, like a winter swimmer surfacing with renewed energy after a cold plunge.

Surviving Ariocarpus, Epithelantha, and Leuchtenbergia plants
Surviving Ariocarpus, Epithelantha, and Leuchtenbergia plants

Epithelantha is another seriously cold tolerant genus. My Epithelantha micromeris var. greggii plants (Cuesta la Muralla, Coahuila, Mexico) all made it; one is seriously damaged, though – it looks like the root is dead while the crown looks fine, so I hope to be able to re-root it. The Epithelantha bokei plants (SB 416; Brewster Co, Texas) also look fine, but due to the extremely dense spination it is hard to say for sure if they are completely undamaged. Strangely the cold has taken the hardest toll on my regular Epithelantha micromeris (SB1327; near Belen, New Mexico) – this variety of E. micromeris is from the northernmost known locality of the species so I had expected the plants to cope better with the frost.

Surviving Obregonia denegrii plants
Surviving Obregonia denegrii plants

Last summer I moved a handful of Obregonia denegrii seedlings (VVZ 163; San Vicente, Tamaulipas) to the coldhouse. I really didn’t expect these plants to be cold hardy, but didn’t have room for them anywhere else. Surprisingly approximately two thirds of the plants survived as illustrated in the above picture (the surrounding pots are not empty, each contain a rather large L. williamsii killed by the cold).

Other success stories are Normanbokea valdeziana, Homalocephala texensis, and Mammillaria meiacantha which all made it through the winter without casualties – the Normanbokea plants are even budding. Acharagma roseana is another species that’s shaking off the winter blues and getting ready to bloom – in general Acharagma seems to handle the cold pretty well, even most of my yearling Acharagma aguirreana seedlings survived. Most Escobaria and Echinocereus obviously had minimal problems with the frost.

Frost killed Lophophora williamsii turning to mush
Frost killed Lophophora williamsii turning to mush

As mentioned above the majority of my larger, regular Lophophora williamsii plants were killed by the frost, but the more tender Lophophora species like Lophophora diffusa and L. fricii are completely eradicated – I’ll probably not experiment further with these species in the coldhouse, the exception maybe being montane varieties of Lophophora fricii.

Dead Lophophora diffusa
Dead Lophophora diffusa

Other species that are completely wiped out include Matucana madisoniorum, an unknown Echinopsis hybrid, Ferocactus glucescens (PP 1354), Lithops lesliei (not exactly a cactus, I know ;-), and Harrisia jusbertii. Surprisingly all my Mammillaria grahamii also died – I had expected this species to be more cold hardy.

Most of my saguaro cactus (Carnegiea gigantea) also succumbed to the frost – 4 plants look like they might survive, most of them badly damaged, but it is too early to say.

I need to start building a new collection of grafting stock – all Trichocereus plants that I grew in the coldhouse are dead, including Trichocereus pachanoi, T. peruvianus, Trichocereus 'Tom Juul’s Giant', and a Penis Cactus… they are all gone. Even plants that were well prepared for the winter died, so Trichocereus is definitely not as tolerant to frost as I had expected.

Decomposing Trichocereus plants
Decomposing Trichocereus plants

To put the death toll into perspective this is the coldest winter in 14 years in Denmark (followed by March, a month with the most extreme temperature fluctuations in 14 years, which were not very becoming to my struggling plants either). The frost set in just before Christmas and only lifted again in the beginning of March. The lowest temperatures measured in the area were as low as -15 C (5 F).

Outdoor temperature in late January
Outdoor temperature in late January

Once in a while short bursts of thaw set in quickly followed by frost (as indicated by the above graph), making the conditions even harder for the plants.

Outdoor temperature in mid February
Outdoor temperature in mid February

The temperature measurements come from a semi-professional weather station located approximately 1.5 km (~ one mile) from where I grow my plants, so these temperatures are representative for those that my plants where exposed to.

To end on a positive note I expect the frost to have killed off many pests also (including red spider mites). Also, I got an affirmative confirmation that it is actually possible for peyote to survive rather extreme conditions in an unheated greenhouse in Denmark... and I got plenty of room for new plants ;-)

Sunday, March 21, 2010

Acharagma roseana – flowers and fruits

To be honest, Acharagma roseana plants are not particularly ingratiating – the flowers are not breathtaking nor is the spination stunning. To me, the attraction of A. roseana lies in its close relationship with Lophophora and Obregonia, making it an obvious candidate for hybridization experiments.

Acharagma roseana flower with pale yellowish tepals with brownish pink midveins
Acharagma roseana flower with pale yellowish tepals with brownish pink midveins

Gene sequence studies by Butterworth et al. (2002) suggest that Acharagma belongs in a well-supported taxonomic clade with Lophophora and Obregonia. They sum up their results as follows:

LOPHOPHORA CLADE. Although there is strong support for this clade (87% bootstrap, 5 decay steps), few morphological features unite this clade. All members have napiform or carrotlike tap-root systems, although these features are also found in other members of the tribe.

The two species of Acharagma have been a source of taxonomic confusion. […] The rpl16 intron data suggest the removal of these two species from Escobaria, placing them in a well-supported (bootstrap 87%, decay 5) clade containing Obregonia and Lophophora, the latter shown to be polyphyletic based on this topology.

(the closing remark on Lophophora being polyphyletic is an interesting statement in its own right, but that’s a whole other story)

Acharagma roseana flower with pink tepals with darker red-tinged midstripe
Acharagma roseana flower with pink tepals with darker red-tinged midstripe

In The New Cactus Lexicon, Hunt describes this species as Acharagma roseanum - I’m not sufficiently well-versed in the Latin language to say which form of the name is correct, but according to this site on botanical Latin the specific epithet must match the genus name in gender. As Acharagma is from the Greek a, without, charagma, groove (the gender of which, according to Hunt, is neuter) this would warrant the “-um” ending. I’m a firm believer in applied laziness so I’ll stick to the (apparently erroneous) “-a” ending for a wee bit longer and avoid having to re-label my plants ;-) Hunt accepts two subspecies: ssp. roseanum and ssp. galeanense, the latter having more spines and slightly larger, cylindrical bodies, compared to the egg-shaped body of the typical form.

Comparison of the two different color forms of Acharagma roseana flowers
Comparison of the two different color forms of Acharagma roseana flowers

The Acharagma roseana plants featured in this post were started from seed in 2005 and flowered freely last summer. As mentioned I would like to use these plants for hybridization experiments with Lophophora but I still need to come up with a good protocol for avoiding self-pollination. The locality information for these specific plants is: LX 578; Ramon Arizpe, Coahuila - “Ramon” should probably read “Ramos” but I'll stick to the information from the vendor’s seed list.

Acharagma roseana with fruits
Acharagma roseana with fruits

Like most other parts of Acharagma roseana the fruits are not showy either. They are an inconspicuous yellowish green color, but have a surprising, not unpleasant, tart taste reminiscent of gooseberries.

The plants grow in my unheated greenhouse and I hope they survive the month long cold snap that is just now loosening its grip of Denmark.

Monday, September 24, 2007

Dirk’s collection of cristate and variegated cacti

Dirk is a lucky man. Anyway, judged by the quality of his collection of crested and variegated cacti, he has to be ;-) I think you’ll agree after seeing the pictures that Dirk has been kind enough to let me share in this post.

Ariocarpus retusus var. elongata crest
Ariocarpus retusus var. elongata crest

I’m particularly fond of this photo of a cristate Ariocarpus retusus, resembling a plant creature one would not be too surprised to encounter in a Tolkien novel.

Dirk is living in Belgium and knows a commercial cactus grower in Holland who lets him pick and choose interesting seedlings when he’s visiting (to stock up on Harrisia for grafting). On this account Dirk has got quite a collection of variegated Lophophora.

Lophophora williamsii f. variegata
Lophophora williamsii f. variegata

I especially like the pastel pink, yellow, and green colors of the above plant – it’s almost a wine gum look-alike ;-) But the rest of the collection is definitely also nice.

Lophophora williamsii f. variegata grafted on Harrisia
Lophophora williamsii f. variegata grafted on Harrisia

Lophophora williamsii f. variegata 'Zebra'
Lophophora williamsii f. variegata 'Zebra'

Collection of variegated Lophophora williamsii
Collection of variegated Lophophora williamsii

Dirk also has plants showing dichotomous branching like these beautifully symmetric two-headed Obregonia denegrii and Lophophora williamsii plants.

Two-headed Obregonia denegrii
Two-headed Obregonia denegrii

Collection of two-headed Lophophora williamsii
Collection of two-headed Lophophora williamsii

Last I heard from Dirk he had just returned from a visit to the 2007 ELK. He had tried to obtain a cristate Lophophora – unfortunately without any luck. You can see more of Dirk’s amazing collection at his cactelders web site.

I hope you enjoyed this featured collection - if you have pictures or information you would like to share, you can drop me a mail at “lophophora [dot] blog [at] gmail [dot] com”.

Tuesday, February 28, 2006

Lophophora williamsii and Obregonia denegrii from seed

Today I sowed this years first batch of seeds - 30 each of:

  • Lophophora williamsii (VM 305k; Sierra de la Paila, Coahuila)
  • Lophophora williamsii (VM 183k; Hipolito, Coahuila)
  • Obregonia denegrii v. prerovskyana nom. prov. (KMR 38; Cinco de Mayo, Tamaulipas)
Allegedly O. denegrii v. prerovskyana has smaller tubercles than the typical form of the species and long cream/pink flowers - I'll find out for sure in 10 years time ;-). The seeds were bought at Kaktusy Ryšavý and sown in a mix consisting of equal parts of limestone gravel, loamy sand, and regular soil. Last years crop As described on the Growing cacti from seed page I'm sowing my seeds in pots placed in plastic bags. Usually the pots are removed from the bags after some weeks but last years Lophophora seedlings have spent a full year secluded in the bags! Lophophora williamsii seedlings (RS 428A; Cuatro Ciénegas, Coahuila) Lophophora williamsii seedlings (RS 428A; Cuatro Ciénegas, Coahuila) It's amazing that cactus seedlings can thrive for a year in the humid environment of a sowing bag (notice the green stuff among the seedlings - it's moss!), but it seems to become them well. Lophophora diffusa seedlings (RS 1193; Peña Miller, Queretaro) Lophophora diffusa seedlings (RS 1193; Peña Miller, Queretaro) The benefits of growing in bags are many, e.g. you don't need to water often and most pests like red spider mites are avoided (on the other hand you have to be careful not to let in sciarid flies). On the downside, the plants seem slightly leggy - probably because they haven't been fully dormant throughout winter.

Monday, August 22, 2005

Obregonia and Ariocarpus from seed – IV

The sowing bags have been open for the last week, and yesterday the seedling plants were removed from the bags and fully exposed to the real world environment. The 30+ Obregonia denegrii (VVZ 163; San Vicente, Tamaulipas) seedlings are growing vigorously, and I’m already wondering how to find room for all the plants ;-)

Obregonia denegrii seedlings
Obregonia denegrii seedlings

The 6 Ariocarpus fissuratus (PP 176; Big Bend, Texas) seedlings also started out convincingly but after growing a couple of diminutive tubercles each, their growth grinded to a halt. I’m a bit disappointed with the germination rate of these A. fissuratus seeds and will probably try again next year with seeds from a different supplier.

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Monday, March 14, 2005

Obregonia and Ariocarpus from seed - III

Very few of my Ariocarpus fissuratus seed have germinated. Currently I have 3 thriving seedlings - and a corresponding number that dampened off. I'll keep the seedlings in a varm, humid environment for a while; hopefully more seed will germinate. I'm not sure if I'm treating the seed wrong, if the quality of the seed were inferior, or if A. fissuratus is just hard to grow from seed.

The germination rate of the Obregonia denegrii seed is close to a 100% (the seed were treated in exactly the same way as the A. fissuratus seed). The seedlings have been moved to a slightly cooler location, and soon I'll slowly introduce them to the harsh world outside the growing bag.

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Sunday, February 13, 2005

Obregonia and Ariocarpus from seed - II

Two days ago, at the beginning of the weekend, there were not many signs that the Obregonia or Ariocarpus seed would germinate. Tonight more than half of the Obregonia and a few of the Ariocarpus seed had germinated.

The seedlings still have a pale, yellowish hue - hopefully they will take on a healthier chlorophyll-green in a couple of days.

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Saturday, February 05, 2005

Obregonia and Ariocarpus from seed

It’s probably too early in the year, but today seemed like a good day for sowing:


  • Obregonia denegrii (VVZ 163; San Vicente, Tamaulipas)
  • Ariocarpus fissuratus (PP 176; Big Bend, Texas)

The seed (30something of each species) were handled as described in “Growing cacti from seed”.

I’m holding my Lophophora seed back – I’m planning on sowing an indoor batch in early spring and a cold house batch in late spring.

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