Magnolia kobus, stellata, and x loebneri (with a little bit about hybrid naming)

In my last post about the Saucer Magnolia, I mentioned there was another popular magnolia also blooming now: the Star Magnolia or Magnolia stellata. It's very closely related to the Kobus Magnolia (Magnolia kobus), to the point where some taxonomists consider it the Star Magnolia to be a variety of it (Magnolia kobus var. stellata). There is also a hybrid of the Kobus and Star Magnolia, the Loebner Magnolia, Magnolia x loebneri.

Magnolia x loebneri 'Merril'

As I mentioned last time, the Saucer Magnolia (Magnolia x soulangeana) is a hybrid of two asian Magnolias: The combination of the Yulan Magnolia (Magnolia denudata) as the seed parent, and the Lily Magnolia (Magnolia liliiflora) as the pollen parent. So where does the "x soulangeana" part of the name come from? Some hybrids, particularly those which are either naturally occurring or common in the trade with many named cultivars, will be formally named and described by botanists. This allows the Saucer Magnolia to have a slightly less complicated botanic name, as were it not described, the plant would be referred to by using a hybrid formula (Magnolia denudata x liliiflora), which gets to be a bit unwieldy.

Rarely, you might actually see described intergeneric hybrids (pollen and seed plants of two different genera), such as x Sorbaronia alpina, a hybrid between Sorbus aria (Whitebeam) and Aronia arbutifolia (Red Chokecherry).  In this case, since the hybrid is between two species of two different genera as opposed to between two species of the same genus, the "X" proceeds the name of the genus, which in this case is an amalgam of its two parent genera.

A graft where the stem (above) is noticeable outgrowing the
rootstock (below). From Wikipedia's article on Grafting. 

Even more rarely, you might see a name resembling the above, but proceed by a "+", as in +Crataegomespilus. This indicates a graft chimera between Crataegus (Hawthorn) and Mespilus (Medlar). Graft chimeras are weird, there's no way around it, and two my knowledge there are only a scant few known to exist.
For those who may be unaware, grafting is basically when you take the stem of one plant, and attach it to the rootstock of another plant. This is commonly done with fruit trees: you don't necessarily want to let your apple trees get up to 40 feet tall since that makes it a lot harder to harvest the fruit. By taking the stem of the apple tree you like the fruit of and grafting it to the rootstock of a smaller growing apple tree, you can control the adult height of the plant. I unfortunately don't have any of my own photos of the process to share, but there are many available at Wikipedia's article on Grafting.
The graft in the photo above is quite clean, but in many cases the rootstock may send up stems of its own as well.

A graft chimera is when the resulting grafted plant has three distinct types of shoots or stems: shoots of the grafted stem, shoots of the rootstock, and shoots which oddly enough have characteristics of both of the plants. These are quite rare, and you're unlikely to come across them, but I think its an interesting example of some of the odd things that plants can do.

Moving back to Magnolias, we'll start out with a straight species...

Kobus Magnolia (Magnolia kobus)

An old, now deceased Kobus Magnolia at the Arnold Arboretum

I've seen the Kobus Magnolia quite frequently in Botanic Gardens, but less frequently in the residential landscape. I suspect it's displaced in the trade by the Star and Loebner Magnolias, as those tend to flower a bit more heavily as well as at a younger age. I find the flowers of the Kobus Magnolia to be a bit larger in general however.

The species is native to Japan mostly, though is also found in South Korea. The name "Kobus" is apparently dervied from the Japanese common name for the species, Kobushi. I have no idea what kobushi means.

Embarrassingly enough, I don't currently have a picture of the Magnolia stellata (Star Magnolia), though I did heavily photograph the one at the Rose Kennedy Greenway during my two years there. Here's a link to a 4/25/11 article I wrote on the species while working there, which includes a good photograph of the plant framed by One International Place in the background.

The Star Magnolia is actually fairly rare in the wild, currently found only in Honshu, Japan. It has long been in cultivation however, with many popular cultivars such as 'Centennial', ' Royal Star', and 'Waterlily'. The name stellata refers to the shape of the flowers, which resemble stars.

Magnolia x loebneri 'Leonard Messel'

The Loebner Magnolia (Magnolia x loebneri or Magnolia kobus var. loebneri) is a hybrid of the Star and Kobus Magnolias. Like the Saucer Magnolia, its not a natural hybrid, as the native ranges of these two species (or varieties) don't overlap, so they were never really introduced to each other without human help. The hybrid is named for a german breeder, M. Loebner, who made the first hybrids and introduced the species into cultivation.

Magnolia x loebneri 'Ballerina' 

Still cultivated today, It seems to be about as popular as the Star Magnolia, though it has its own niche in the landscape as it tends to grow about 10' higher, owing to its heritage from the Kobus Magnolia. Fortunately, it still flowers at quite a young age/

There are quite a few popular cultivars of the Loebner Magnolia, 'Leonard Messel' (Pictured above) is arguably the most so, owning to its distinct flowers which have petals (well, we should probably use the term "tepals", but more on that later) that are pink on the outside and white on the inside.

'Merril', also pictured above, tends to flower at a younger age than other Loebner Magnolias and is also quite a popular cultivar.

Though I photographed entirely white cultivars save for 'Leonard Messel', pink is not an uncommon color for this species, and many cultivars will have at least some pink, and sometimes flowers which are pink when first emerging from the bud but mature to white. I'm not sure I've ever seen a cultivar with a pure pink flower though.

Magnolia x loebneri 'Ballerina' 

I haven't seen 'Ballerina' quite as much as the other two, but it's a bit smaller than 'Merril', and as is evident by comparing the two photos, it has far more petals (...or tepals) per flower. I'm honestly not quite sure which of the two I prefer... is more petals preferable or does it just make the flower look more crowded? Maybe I'm just waiting for a Star Magnolia that really wows me and I haven't come across one yet. These are probably my least favorite of the spring-flowering magnolias... I prefer the rarer Magnolia salicifolia to it as they seem to flower for a bit longer, albiet never explode into bloom quite as much as the Star and Loebner Magnolias. However, I still enjoy watching the Star Magnolias come into bloom this time of year, and they are probably the first spring-flowering tree I get excited about.

Still have a few more magnolias to talk about, and at some point I'll go into the characteristics of the Magnolia Family (as well as this mysterious "tepal" term I kept trying to drop).