Carl wrote:Not meaning to hijack this thread but how do you not kill these? I've come over funny and purchased some seed
N.D. wrote:KarlR, how do you grow them? I have sown them twice, both times with the same result: They grow fine to about 1cm in size, and then they sit doing nothing, slowly and gradually desiccating to death (not collapsing quickly). I grow them in small clay pots with 75% grit/25% soil, water about once a week (less often in winter), and put them out in the sun for the summer. I suspected they did not like the winter cold (about 15C), but they don't grow in the summer heat either (under direct sun and in the shade alike).
I grow them under artificial lights. They've hardly ever seen a ray of sunshine. I've got two 400W metal-halide bulbs covering an area of a little over 2 square meters. The bulbs produce quite a lot of heat so that means I can (and sort of have to) water frequently. I water them ca. once a week year round and add a very diluted fertiliser probably around twice a month. I could probably water them even more often as I notice that sometimes their buds fail, but I don't want to risk going too far. I currently grow them in a mix of about 25% coco and the rest a mix of grit (pumice, crushed lava etc.). I had them in a completely inorganic mix before this but I can't really say I've noticed any difference either way in terms of how they've been growing. I added the coco because it seemed like their roots are a bit fragile and I thought maybe they'd prefer a somewhat lighter and softer soil than a completely inorganic one.
The amount of heat produced by the bulbs means that the soil dries out very quickly so they're quite happy to be drenched once a week. My thermometer broke a long time ago, but I think the air temperature under the lamps is usually somewhere between 20-30 degrees Celsius depending a lot on the outside temperature and how much I'm ventilating. Like I said, I've never grown these things before but they seem to thrive in this environment. My P. mccoyi plants (though it seems from what I could understand online that this species is now no longer a Pseudolithos?) also thrive in this environment. They have flowered continuously for over a year now. Just took the photo below. I think they're actually all flowering there. No accidental pollination by flies yet, however. Maybe I should put them outside for a couple of days, see if that might attract some attention?
Yes, putting them outside is a good idea, Karl. I remember other posts saying that plants outside attract the tiny flies needed to pollinate these plants, and usually result in seed follicles. Good luck!
Diane wrote:Yes, putting them outside is a good idea, Karl. I remember other posts saying that plants outside attract the tiny flies needed to pollinate these plants, and usually result in seed follicles. Good luck!
Excellent! I'll try it out. Would be fun to get some seeds.
Eric Williams wrote:Hi Karl, exellent plants indeed. When you say you grow them under lights, does this mean they grow through the Winter months as well ? Cheers
Yeah, they grow throughout the year. It's basically constant summer
I'm planning on experimenting a bit with rest periods since I grow a lot of cacti under lights too, so I might give everything a few weeks rest this winter. The Pseudolithos don't seem to mind a lack of a resting period, though it's possible (and probably likely) that they might benefit from it.
Karl R - The second type flowers are indeed odd. I've never seen anything like them. As mentioned these plants hybridise easily. They bring to mind the long lost, described and never seen again P.horwoodii. It even got a colour photo on the cover of British cactus journal many years ago, I have it somewhere and will try find it for you. Would love to draw it
I just took a look at my own P. migiurtinus and its (past) flowers. It struck me that the 'second flower type' looked suspiciously like the stalks (peduncles?) left over after the petals (or whatever the fleshy part of the flower is called in a stapeliad) falls off.
Is it possible that we're looking at just the peduncles and the sepals left over after the actual petals fell off? I imagine the second photo shows what it would look like if the sepals were not to close after the flower fell off...
Astro - I've just looked through a load of photos my plants and I think you are right, well spotted. With my plants everything tends to dry up and shrivel up very quickly once the flowers come to an end - usually in full sun in a greenhouse. Perhaps growing under lights with more humidity means these remains last a little longer. I guess a close up picture is what we need.
Lithos and Astro, I agree that the second type of flowers resemble the dried up remains of the flowers of P. migiurtinus. I have no idea what the proper word would be for these remains - I assume you mean the remains that persist on the inflorescence, not the parts of the flower that fall off when dry? However, this plant has never had any other kind of flower than this so they cannot be the remains of flowers. This plant along with one other were the first to flower for me last year and I took particular notice of them to see what they would look like.
It has flowered a few more times since then, and although I haven't paid particular attention to it, I will usually have a look at my plants a couple of times per day and I've never noticed this plant with any other kind of flower.
There is also the sticky liquid on the flowers that you can see in the photo. None of the flowers on my other Pseudolithos produce anything like this (nor do the remains). Even the plant has on occasion exuded some kind of liquid like this from the top of the stem where it has crystallised. I haven't any photos of it as I simply imagined this to fall within the normal behaviour of these plants, and right now most of the crystallised liquid was washed away last time I watered them. The liquid produced by the flowers reminds me a bit of the one produced by the female flowers on Euphorbia obesa. I'm not sure whether it's nectar or something else.
The flower remains dry out very quickly on the other Pseudolithos. The relative humidity under the lights is perhaps slightly higher than in an ordinary greenhouse, but nothing significant. These flowers opened and appeared as you see them and persisted for days before closing and drying out. No part of the flowers have fallen off though. Everything has just dried up and persisted on the inflorescence.
So, all in all, they can't be the remains of flowers. However, the thought has struck me before that maybe this plant is some kind of freak with flowers that for some reason don't fully develop before opening. Some strange mutation perhaps. I haven't been able to find any photos online that even resemble these flowers. I suppose a hybrid origin would be possible too, though it seems strange that if the parents had more "normal" looking flowers the offspring would end up with these kind of flowers.
I will try and take some more (and better) photos of it the next time it flowers. I have a tripod now so it'll be easier to take good quality close-ups.
