Irwin
Stenocactus multicostatus zacatecasens
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Stenocactus multicostatus zacatecasens
Recently, I captured this cactus blooming. I particularly like the numerous ribs that distinguish thihs family of cactus. Hope you enjoy.
Irwin
Irwin
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crotermund
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Bruce Williams
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A nice photo Irwin and a plant that brings back memories for me. I'm sure it used to have a different generic name - but I can't remember it (I'm gettin' old) 
I've always thought that, although very attractive, the numerous deep ribbing of this genera were a bit of an anomaly in the cactaceae.
The general thesis holds that the extreme adaptation of cacti into globular or cylindrical shapes* is primarily to achieve the greatest possible ratio of volume to surface area, with the purpose of reducing water loss through respiration. So the ribbing of this genera (greatly increasing surface area) would seem to work in opposition to that purpose?
Obviously must have a purpose though - maybe the wavy ribs aid in the condensation of water from dew or mist like the bizarre
spination on some other cacti - or maybe not
Bruce
*ok there are many other exceptions, opuntias and the various epiphytic genera for example
I've always thought that, although very attractive, the numerous deep ribbing of this genera were a bit of an anomaly in the cactaceae.
The general thesis holds that the extreme adaptation of cacti into globular or cylindrical shapes* is primarily to achieve the greatest possible ratio of volume to surface area, with the purpose of reducing water loss through respiration. So the ribbing of this genera (greatly increasing surface area) would seem to work in opposition to that purpose?
Obviously must have a purpose though - maybe the wavy ribs aid in the condensation of water from dew or mist like the bizarre
spination on some other cacti - or maybe not
Bruce
*ok there are many other exceptions, opuntias and the various epiphytic genera for example
Echinofossulocactus you are thinking of Bruce!
Stenocactus has now been resurrected in The New Cactus Lexicon saying:-
"The generic names Stenocactus and Echinofossulocactus have both been in common use for this genus, but the latter name was originally based on plants referable to Echinocactus sensu stricto."
DaveW
Stenocactus has now been resurrected in The New Cactus Lexicon saying:-
"The generic names Stenocactus and Echinofossulocactus have both been in common use for this genus, but the latter name was originally based on plants referable to Echinocactus sensu stricto."
DaveW
Beautiful Picture Irwin, Excellent colors. maybe the ribbing acts like a Radiator to dissipate heat? I have one of these but it has never flowered yet and the spines on mine at the top are over an inch long (will need to take a picture 
)
)Take Nothing but Pictures--Leave Nothing but Footprints.
Doug Breda
Doug Breda
Thank you Craig, Dave, Bruce and Doug for your thoughtful comments.
Bruce raised an interesting question about the possible evolutionary benefit of the extremely numerous and deeply furrowed ribs of these small cacti from the Chihuahuan desert in Mexico. My guess is that it has to do with shielding large areas of the plant from the scorching sun. Because of thier deeply cut and wavy nature, the no part of the plant remains in the direct sun for too long a period, except for the extrememly thin tops of the ribs. The ribs also increase the surface area of photosynthetic activity. I also think that Bruce is right about providing more surface for water to condense on and a means of channelling it to the roots. Another possible theory is camouflauge (I imagine this little guy would be tough to spot if it was in grassland.
Unfortunately, my books are pretty useless. Later today, if I get the chance, I will check the internet to see if I can get the anwer to several questions I have:
1. Does it grow in grassland, under another plant, or exposed.
2. Does it grow in highly reflective soils
3. At what altitudes does it grow
4 What are the condensation patterns
Bruce, I think there is also an interesting anomoly in the shape of cacti. While many trend toward rounded forms, on one hand, they also tend to trend away from pure roundness with series of nipples, ribs, and chins on the other hand.
Dave, all of my seed grown plants have a special place in my heart. You must be proud of your two headed friend. Please post pics.
Regards from Dallas.
Irwin
Bruce raised an interesting question about the possible evolutionary benefit of the extremely numerous and deeply furrowed ribs of these small cacti from the Chihuahuan desert in Mexico. My guess is that it has to do with shielding large areas of the plant from the scorching sun. Because of thier deeply cut and wavy nature, the no part of the plant remains in the direct sun for too long a period, except for the extrememly thin tops of the ribs. The ribs also increase the surface area of photosynthetic activity. I also think that Bruce is right about providing more surface for water to condense on and a means of channelling it to the roots. Another possible theory is camouflauge (I imagine this little guy would be tough to spot if it was in grassland.
Unfortunately, my books are pretty useless. Later today, if I get the chance, I will check the internet to see if I can get the anwer to several questions I have:
1. Does it grow in grassland, under another plant, or exposed.
2. Does it grow in highly reflective soils
3. At what altitudes does it grow
4 What are the condensation patterns
Bruce, I think there is also an interesting anomoly in the shape of cacti. While many trend toward rounded forms, on one hand, they also tend to trend away from pure roundness with series of nipples, ribs, and chins on the other hand.
Dave, all of my seed grown plants have a special place in my heart. You must be proud of your two headed friend. Please post pics.
Regards from Dallas.
Irwin
You may find some of your answers here Irwin, try under Distribution etc:-
http://saimon.softech.cz/
DaveW
http://saimon.softech.cz/
DaveW