
Bang! I was inspired to photograph this alpine yucca after Judy Newton, UBC Botanical Garden's soon-to-be-retiring education coordinator, featured it in a lecture on Tuesday. Despite being native to New Mexico and Arizona, this plant does quite well in our well-drained alpine garden. Not the typical sort of plant one expects to see in Vancouver!
Yuccas have only one group of pollinators: yucca moths. The two sets of organisms have a special kind of relationship called obligate mutualism, in which both organisms benefit from each other, and indeed rely on each other - if one were to go extinct, the other would follow.
The yucca moths are highly specific pollinators for the yucca (not just any insect will do!), so they are necessary if seed production is going to occur. While pollinating the flowers, the yucca moths also lay their eggs. The hatched moth larvae are picky eaters, only feasting on developing yucca seeds (and leaving quite a few behind to germinate into new yucca plants). In short, no yucca seeds, no yucca moths. No yucca moths, no yucca seeds.
If you're interested in further reading on the topic, I'd suggest reading Tegeticula, the yucca moths from The Tree of Life Project, as well as the web page of Dr. Olle Pellmyr from the University of Idaho. Dr. Pellmyr has published a paper asserting that there is evidence to believe that the yucca - yucca moth obligate mutualism relationship has existed for forty million years.
In other news, the latest edition of Tangled Bank is out: Tangled Bank #30 via The Geomblog. Tangled Bank is a “gathering of science weblogs” that promotes the best science weblog writing on a bi-weekly basis (and now switching to weekly). The Botany Photo of the Day submission for this edition was the entry on Raoulia australis, since I figured a shape-heavy photograph would have at least a little relevance to a weblog devoted to computational geometry.
Lastly, I hope everyone reading this is alright with the moderation of comments. For yesterday's photograph, about 25% of the comments were spam, but none of them slipped through because I deleted them before they were made public. I'm not going to moderate out criticism and pointed questions (both of which were received yesterday), but I am going to try and keep out anything inappropriate.





my parents had a plantlike this one but it would grow a stalk & bloom medium size trumpets.it came from my brothers property in Arizona.when it was brought to Illinois,it survived our oddball winters.it sure is a beautiful plant.
These pics are great.Pornography for gardners!
THANKING YOU ON A DAILY BASIS FOR THIS SITE.
WHAT A JOY.
I am not sure, but can't yukka be used in cooking or for medicinal uses? I could be way of base here I don't know
Thank you Daniel I used to teach about the pollination of Yucca but I had forgotten.
You can eat Yucca root. I had one at a Costa Rican restaurant yesterday in Tucson Arizona. Very good. Texture like a potatoe but much sweeter.
Watch out. Those alpine yucca leaves are sharp.
Yea baby
Am unclear on the locality of the yucca moth. Are they dispossessed insects who find themselves as desperate as joseph & mary on christmas eve , wayword out of towners just flying around Vancouver like they took a really wrong turn, or did someone transplant them here?
The yucca moths would only be found in the native distribution range of the yucca. The plants in Vancouver never have seeds, because they are never pollinated.
True Yucca and Red Yucca are very popular in Austin, TX. They withstand our periodic droughts quite well. The reds will bloom most of summer.
thank you to Daniel for the info on the moth situation - warmest regards
I have a yucca planted here in Northwest Arkansas. It is huge and appears healthy but has never bloomed. Is there specific nutrients that I need to fertilize it with?
Thank you!
I love this site, it gives me something to get up for every day. The photos are beautiful, and I get to see some things I never would any other way. Thank you.
I have 3 of these plants and iv been here for 4 summers and this is the first it ever bloomed! Wow it is Fantastic! I live in Ontario Canada up close to lake Simcoe.
I've just found this site & would like to know more about it. I would really like to obtain some good alround info on yucca plants & find what species will do well in the Vancouver area, etc, etc. ....... I'm a bit of a yucca nut!
John Dawe in Richmond, BC.
Hello John,
You should visit the alpine garden at UBC sometime. Here's a list of the Yucca, current as of last winter. If you check the digits on the plant labels, the last four roughly represent the year that the plant was planted - so, in the case of this photograph, this plant has been around since 1993.
My Yucca plant only flowered the once, is there something I need to do to have it continue it's blossoms every year?
I have a yucca plant in my garden whichthis year has produced 12 baby yuccas at its base. Do I just dimply sever these plants and plant them in a new location.
To the previous posters - it is far better to ask these questions on the garden's discussion forums. I'm not a horticulturist, so I wouldn't know the answer, but there is a community of nearly a thousand active users on the forums who might!
Why did our Yucca plant only bloom once in 5 years. the center stem was cut of one year by mistake.
To Bree and Susan,
As far as I'm aware, there aren't many culinary or medicinal uses for Yuccas. The "yucca" served at Costa Rican (and other Latin American) restaurants is actually not this member of the Agavaceae, but rather is Manihot esculenta (Euphorbiaceae), also known as "yuca", "cassava", or "manioc". It is quite widespread in its use throughout much of the Americas as a potato-like root.
To those who wonder about the flowering regime, I believe most (or at least many) species of Yucca are monocarpic, meaning they only flower once in their lifetime. This means they grow for about 2-3 years, flower, and then die. Many plants may appear to live longer, however, because they grow clonally and a new yucca individual can be growing virtually on top of the old one.
that junk is sharp.watch out.great pic tho
I have a yucca that sends up a stalk every four years, then blooms a cream color bell blossom. I'm sure this plant does not die then grow a new one in the same place.