Which Jovibarba?

[Lori S.]

Which Jovibarba would this be?  I'm guessing J. hirta but I know little about these.
All the photos are of the same species.  Its winter colour is red, and it's light green in summer.  The rosettes get to their maximum size in tufa, which is about 1" (2.5 cm), though most are smaller.  Thanks in advance.

[McDonough]

Which Jovibarba would this be?  I'm guessing J. hirta but I know little about these.
All the photos are of the same species.  Its winter colour is red, and it's light green in summer.  The rosettes get to their maximum size in tufa, which is about 1" (2.5 cm), though most are smaller.  Thanks in advance.

The good thing about this question, there are only 5 Jovibarba species; J. allionii, arenaria, heufflelii, hirta, and sobolifera.  Distinguishing J. heuffelii is easy and we know it's not that species, the harder part is distinguishing between the 4 remaining similar species.  

Just took a look through The Sempervivum & Jovibarba Handbook by Peter Mitchell, 1973, but the descriptions of the four species are general and without a key.  I think we can also eliminate J. sobolifera, as that species uniquely produces chicks practically sitting on top of the incurved mother rosettes, rendering a distinctive look.  Generally speaking J. allionii has hairy leaves (can be variable), and J. arenaria has incurved leaves/rosettes much like J. sobolifera, therefore all signs point to your plants being J. hirta with its more open summer rosettes.  

Adding to the difficulty, each species is highly variable, and with a number of regional forms of each; these tend to blur the lines between the species. Take a look at the following excellent Sempervivum and Jovibarba site, here's the link to the Jovibarba pages:
http://www.succulents.jp/photolist_jovibarba_index.html

Tips:  the page is in Japanese, but the species names and regional form names use latin plant names, thus legible.  I have the Google Translate plugin for Firefox, however it will not work on these pages because of underlying HTML frames, but since the plant names are legible, that's okay and the site is still a great resource.  Click on the allionii/arenaria tab, hirta tab, and sobolifera tab, each loads a page with many thumbnail images of species variants and regional forms.  The pages have so many thumbnail images, it can be a bit slow to load.  Simply "mouse over" any thumbnail with your cursor to see an enlarged popup image.  Enjoy, but you might feel more uncertain after looking, because some of the J. arenaria forms look like a possibility for your plant as well

[Lori S.]

That looks like a terrific reference - thanks, Mark!
I'll browse through the pics and see what shakes out.
 

[Todd Boland]

Hmm,....I see no pictures attached?  I have hirta, sobolifera and heufflellii.

(The forum glitch with Lori's photos not displaying has been fixed - Mark McD)

[cohan]

Nice patch, Lori--Sempervivum 'soboliferum' was one of the very first rock garden plants I grew
If I recall correctly, according to some, all of the species other than heuffellii have been lumped into one sp.. globifera, maybe? with subspecies for the old sp (others toss them all back in semp)...
These tend to be among the plants--like many succulents such as Haworthias, Gasterias etc--that I don't attempt to name in my collection if they come without data..lol : the searching for a name is fun and educational, but unless (and even if ) you are pretty sure that its a natural clone and not a garden hybrid, a really positive name seems elusive....

I have some to post in the appropriate section one day soon....

[Todd Boland]

Looks like S. hirta to me...soboliferum (at least mine labelled as such) has rounded tips on the leaves.  Hirta (again, labelled as such), has the finer tips as shown on Lori's plants.  Also my soboliferum stays green all winter while hirta turns purple-tinted.

[Hoy]

Take a look at this:
http://www.stewo.no/stauder_j-k.htm

[cohan]

 Here's a page (forum) that lists descriptions etc by species..
http://sempervivum.aforumfree.com/c4-jovibarba-species-and-cultivars

If you want, Lori, I could post your pic there and see what the semp experts have to say...

[McDonough]

Cohan, that forum requires registration.  I had forgotten about that forum, and checking my records, I do have a login and password, but it tells me the account was inactive too long, and refuses to let me in, requiring to send a message to the forum administrator, which I did.

[cohan]

Cohan, that forum requires registration.  I had forgotten about that forum, and checking my records, I do have a login and password, but it tells me the account was inactive too long, and refuses to let me in, requiring to send a message to the forum administrator, which I did.

oops, sorry, I should have checked the link unlogged!

[Todd Boland]

It looks like my ID's have been switched!  Well nice to kinow their real names.

[Lori S.]

Here's a page (forum) that lists descriptions etc by species..
http://sempervivum.aforumfree.com/c4-jovibarba-species-and-cultivars

If you want, Lori, I could post your pic there and see what the semp experts have to say...

That would be excellent, Cohan!  Thank you very much.  Should I e-mail you the photos posted here or is it possible to copy them from (or link to) this site? 

[cohan]

Ok, Lori-- I'll try just linking to this page...

[cohan]

I finally go this linked over to the Semp forum; the responses agreed most likely Jovibarba globifera hirta (also called Sempervivum globiferum hirtum or J hirta);
Though it was noted that growing conditions could result in notable variation, and a close-up of a rosette showing leaf detail would be helpful...

[Lori S.]

Thanks very much, Cohan.  It's a bit hard to get a focused close-up in the twilight this evening but these show the bristly edges to the leaves.  I can get better photos tomorrow night or on the weekend.  I don't have any photos of the flowers at all (not that it was asked for).