Dasylirion longissimum

[GreekDesert]

Dasylirion longissimum Lemaire is different from Dasylirion quadrangulatum

[Geoff]

I understand the experts say it is different... I am just unclear HOW it is different. Be nice to see some photos of these side by side.

[GreekDesert]

One of the differences of Dasylirion longissimum and Dasylirion quadrangulatum are
the leaf characters.The leaves of Dasylirion quadrangulatum are quadrangulate, the
leaves of Dasylirion longissimum are not quadrangulate (picture 2).
D. quadrangulatum has no prickles on the leaves but D. longissimum has a few near
the spoon.

[mickthecactus]

I grew this from seed years ago. It is the world's slowest growing plant......

[Paul S]

Typically Dasylirion longissimum is much scruffier in appearance than its more northern cousin and has a thinner trunk.

D. longissimum



D. quadrangulatum



In the field they are easy to tell apart - the populations are a few hundred km apart!

I would have said, though, that the leaves are quadrangulate - certainly from the middle to the end. Maybe flatter nearer the spoon. Also the prickles are generally only at the very base of the leaves right by the spoon. The plant in your pic actually looks more to me like a hybrid - the prickles are very pronounced and the leaves quite flat. Hybrids do occur - both naturally and in cultivation - I have one that came from a batch of D.q. seeds that started life just as yours looks now.

[Shmuel]

Not quite sure how to post this, but here is a photo of D. longissimum herbarium specimen from Kew. http://apps.kew.org/herbcat/getImage.do ... K000524955" onclick="window.open(this.href);return false;

Note that the 1902 collection name was D juncifolium.
Trouble is that http://www.theplantlist.org/tpl1.1/record/kew-303968" onclick="window.open(this.href);return false; calls D juncifolium a synonym of D quadrangulatum. Maddening.

Shmuel

[Meangreen94z]

Here is a good reference on how to identify based on leaf base.

[jam]

Dasylirion longissimum at the botanical garden in Barcelona, 02/2023

[Azuleja]

Dasylirion at a nursery in CA

Dasylirion-longissimum-scaled.jpg (653.33 KiB) Viewed 843 times

1708738008023.jpg (580.72 KiB) Viewed 843 times

[Tom in Tucson]

Dasylirion at a nursery in CA

Dasylirion-longissimum-scaled.jpg

1708738008023.jpg

These are more likely to be the almost identical species Dasylirion quadrangulatum

See this post: viewtopic.php?p=62796#p62796

[Azuleja]

Dasylirion at a nursery in CA

Dasylirion-longissimum-scaled.jpg

1708738008023.jpg

These are more likely to be the almost identical species Dasylirion quadrangulatum

I will check the leaves the next time I'm there!

[Azuleja]

Dasylirion at a nursery in CA

Dasylirion-longissimum-scaled.jpg

1708738008023.jpg

These are more likely to be the almost identical species Dasylirion quadrangulatum

See this post: viewtopic.php?p=62796#p62796

I finally got around to checking the leaves more closely at the nursery. I think both species are represented in the display photo. I snapped a few more photos and found one that may be a hybrid. They're all labeled Dasylirion longissimum. The plants were acquired at different times from different growers, some correctly labeled and some not.

Dasylirion longissimum

Dasylirion longissimum.jpg (225.65 KiB) Viewed 240 times

Dasylirion quadrangulatum

Dasylirion quadrangulatum.jpg (212.23 KiB) Viewed 240 times

Possible Dasylirion hybrid

Dasylirion hybrid.jpg (192.85 KiB) Viewed 240 times

[Paul S]

That looks just about spot on

My biggest D.q is set to flower this year so I'll update this thread with pics as it develops.