Label

Comparison

Comparison

It looks like Osmanthus fragrans Lour var thungbergii is a real variety by a search. Thunbergii is similar in hardiness to auranticus. Or at least if it's labeled correctly it's of the thunbergii variety, which is similar hardiness to the O. auranticus.

nurcar.com has a bunch of varieties you can look at their pictures. But the Thunbergii varieties don't really have smaller leaves that I can tell. These pictures are from their site.

Is Amsterdam warm in the winter to support O. fragrans? I know the O. fragrans x O. Heterophyllus crosses like O. x fortunei are hardy. I have an O. fortunei, but it's too small to know what the leaves will look like when they're fully grown. The leaves from that Osmanthus look a bit serrated, which make me lean towards a O. heterophyllus cross...

Thanks ocelaris! I checked the links you gave...Definately it's not Osmanthus fragrans Lour var thungbergii 'cause this one has much smaller leaves with a different texture. They resemble o. x fortunei leaves but are less serrated.
Yes, Amsterdam is warm enough for osmanthus fragrans...It's in 8b climate zone. So it could easily be a variety of o. fragrans... I just need confirmation.

This post was edited by misha74 on Tue, Aug 26, 14 at 10:52

Juvenile leaves of both varieties are serrated, where as adult leaves of all Osmanthus have little if any serration. So it's probably just an adult form. It does look like Osmanthus Heterophyllus leaves are much smaller than Osmanthus Fragrans, with Osmanthus x Fortunei being in between (because it's a cross of the two).

The more I look at that plant the more I am sure it's an Osmanthus Heterophyllus. It's possible it was an O. Fragrans grafted on an O. Heterophyllus root stock and the root stock over grew it? Or it could just be mislabled.

It would be interesting to know if the plant flowers in the fall or throughout winter, and the color of the flowers. Because Osmanthus Heterophyllus and Fontunei flower only in the fall and Osmanthus Fragrans will flower throughout the winter. I might be wrong, but I think that is the case. Also flower color will give some hint as again I believe (but am not 100% sure) that only Osmanthus Fragrans have yellow, orange and white flowers; all others being white. If it had yellow flowers it would probably be an Osmanthus Fragrans, maybe just a variety that has smaller leaves. I have an Osmanthus Heterophyllus which is miniature and has 1-3cm (1/4" - 1/2" leaves). So it's likely that heterophyllus has smaller leaves in it's gene pool.

This page has a lot of various pictures of all the Osmanthus, one of the best on the web:

Osmanthus on Oregon State University's Website

You can see adult and juvenile leaves in this picture of an Osmanthus Fortunei (O. Fragrans x O. heterophyllus).

Here is an adult Osmanthus Fortunei:

Here is an Osmanthus Heterophyllus both adult and juvenille leaves:

Adult leaves of Osmanthus Heterophyllus:

This post was edited by ocelaris on Tue, Aug 26, 14 at 11:34

Hard to tell what that osmanthus is in the Botanical Gardens.

Perhaps Osmanthus delavayii

Amsterdams high in the summer is 60 degrees.
Its not just the cold temps that matter, even though AMsterdam does get cold in the winter.
For a high of 60 degrees for the hottest months of the year, the zone is definately NOT 8b in the US.
A sweet olive needs it much warmer than that.
I don't know what kind of tree that is in Amsterdam, but I am sure its not a Sweet Olive tree.

A USDA zone only specifies the lowest average extreme temperature, they don't specify high temps or heat levels. So technically, it could be an 8B zone, although that doesn't tell us exactly how well Osmanthus fragrans would do. The pacific northwest coast is 8B, because it's maritime climate.

I think we all agree that the leaves don't match up with O. fragrans; but I would hesitate to say that they can't grow there. I think a similar comparison would be if O. fragrans can grow in the Pacific North West or Northern California in the US. Doing a bit of googling, it appears most do not do as well, but it seems poor drainage is more the limiting factor.

Given that this is a botanical garden who knows if they were able to provide it with better conditions, and it could be a one off situation. I think the reason that the English grow Osmanthus delavayii is because it tolerates cool better than O. fragrans; and the leaves look much closer to delavayii than O. fragrans. But most Osmanthus delavayii that I have seen are more "shrubby" like a Forsythia than a tree which the specimen clearly is. It may be a cross between delavayii and fragrans, because it's habit looks more like O. fragrans than anything else.

Thank you ocelaris! Your post is very helpful. I think that now we're on the right track ;)