Sempervivum and Sedum Oddities

Crested Plants
The crested condition has several possible causes, two of which are genetic and environmental causes. It can also be caused by hormonal, fungal, and bacterial disease. Whatever the cause, it can produce some very interesting sempervivum and sedum specimens in our gardens.
It is by chance that in 2012 I found a crested stem growing in a large clump of Petrosedum forsterianum ‘Silver Stone’. I isolated the stem and potted it up. I am finding that I do have to be diligent in cutting out any normal type of growth in order to keep the crested plant from being overcome by normal growth. It is growing into a nice colony, showing woody stems and heavy cresting.
It seems that it is not that uncommon for ‘Silver Stone’ to form crested stems.

The Sempervivum ‘Fuzzy Wuzzy’ from Kevin Vaughn’s breeding program seems to be genetically inclined to making crested offsets, as does one of its parents, S. ‘Denise’s Cobweb’, introduced by Patty Drown.


Here we have a Crested form of S. tectorum from Costigliole, Piemonte Mts, Italy, that appears to be crested, maybe from damage to the young offset. I have had this Sempervivum for four years and have not had any other crested offsets in the colony. In its second year the crested offset is starting to produce what looks to be normal offsets.


Sports
A sport shows morphological differences from the rest of the plant. Sports may differ by foliage shape, color, flowers, or branch structure.

A sedum that occasionally forms crests is Petrosedum rupestre subsp. rupestre ‘Sandy’s Silver Crest,’ which was a sport found by by Sandy MacPherson. Here is what Kevin Vaughn has to say about this wonderful plant that is a sport and can also form crests.

JungleShadows said:OK here's the story of Sedum 'Sandy's Silver Crest'.
Sandy MacPherson had a nursery in OH that sold mainly semps but he did grow some sedums as well. Helen Payne and he were good friends and he shared this sedum sport with Helen. After growing it for several years she realized how outstanding it is and named it 'Sandy's Silver Crest'. It is a very peculiar plant in that it is not really variegated, but once in a while along a stem, you will get a little portion that is white, maybe 8-10 leaves and then it starts growing green again. This one also crests and if you get the white phase and the crest phase to occur in sync, you get this amazing looking sort of checkerboard cockscomb. This is one that Polly Bishop had and loved and I got a plant back from her before she passed.
It is obviously a reflexum type. I don't know of any commercial source for it, but it's probably one that should be on the market as it's so unique.Kevin

Kevin has been working on a hybrid seedling from ‘Sandy’s Silver Crest’ in order to get more of the bright white leaves and less green. So far it is looking really good.


Here we have some very interesting sempervivums that can morph back and forth with unusual growth forms that are not crested.

Occasionally an 'Oddity' offset forms normal leaves, but many times this normal-looking rosette will slowly revert back to having tube-shaped leaves. You can see that happening in the large rosette in the second photo. A year later that rosette sent out a large bloom stalk. Unfortunately, all but one or two flowers were sterile, resulting in only 3 seedlings from a cross with a large red sempervivum. It is very unusual for 'Oddity' to bloom. It may take a mature colony to get it to bloom.

Only time will tell whether any of the three seedlings will earn a name.

This is a really beautiful and interesting sempervivum. A colony of 'Fame' can go years without producing 'Monstrose' offsets, but when it does, what a sight it is to see.

This rosette went on to produce many 'Monstrose' rosettes, only to revert to 'Fame' the following year. The second year some of the rosettes changed back to 'Monstrose'. What fun.

This wonderful semp has tube-shaped leaves that are closed at the tip, unlike the 'Oddity' leaves, which are open at the tip. 'Grigg's Surprise' has much smaller rosettes than 'Oddity' and a blue-green color. It is also much slower growing. I look forward to have this tiny colony bloom some day.


The lovely ‘Rita Jane’ is no plain Jane. Her contrasting spring colors stand out in a bed. She is listed in this article because of what she does in spring. Notice the odd raised areas on her leaves? Every spring these appear for about a month, then disappear until next spring.


Our gardens are full of surprises, all we have to do is take the time to see what is waiting to be discovered.