Kyle and I first saw Petalidium lanatum adjacent to our first living, in-situ Welwitschia, if that tells you anything. Yep — the Namib Desert. Home to some of the most intense sand storms on Earth, and where decades pass without a millimeter of rain. You think you have it bad?

Sister species of (or, err, maybe synonymous with) Petalidium halimoides — check that page out.

For a plant with such a gnarly attitude, it sure has precious, innocent, tiny red flowers. Note the infructescence that has become woody and spiny with age (yes, just like you).

Subsequent photos: I need you to pay close attention to this. Photo was taken just as we entered the true Namib Desert. This plant looks absolutely toasted – DEAD. A skeleton of sorts, like all those ship wrecks on the Atlantic coast of the desert. But: WRONG! You’d be wrong wrong wrong if you guessed it, just as I did. This plant is actually quite alive. perhaps just a leaf or two per branch, but: that counts as ALIVE… and it was even flowering. This species can hold its own with any pirate.

Scope out the tap root: even longer than that of P. halimoides. That thing is decades old, to be sure..

In the last photo you can see it dominating the landscape (as it is wont to do).

Wild collected, Namibia, Tripp & Dexter #879 (RSA-POM); Photo by Erin Tripp

Wild collected, Namibia, Tripp & Dexter #4108 (RSA-POM); Photo by Erin Tripp

Wild collected, Namibia, Tripp & Dexter #4112 (RSA-POM); Photo by Erin Tripp

I sort of have a thing for this plant. It’s true. Not quite like the Roger Federer thing, but…

I would put up some Vegas chips on hypothesis that this is among the top 100 hardiest species of plants in the world. Well, together with Petalidium lanatum (no doubt its sister species, or maybe I should sink the latter into the former….). Petalidium halimoides is also an opportunist. Above, you see it in several contexts: lush-ish fields and extremely dry, vegetation-less soils of the Namib Desert. Yep – it does it all. Something to aspire to.

First photo: check out the stellate trichomes that you can see with naked eye.

Second photo: check out the Martian taproot.

Third photo: Kyle doing his amazing thing. And note plant abundance. Petalidium halimoides dominates many landscapes, including much of the Kaokoveld.

Fourth photo: Look at those amazing fruiting heads (=infructescences) that the Lucinda McDade-ster is holding (also note her awesome plaid shirt). These fruiting heads become woody and spiny with age… just like the rest of us.

Seed predation is such a huge debacle in ultra-arid deserts that my personal hypothesis is: this ‘head-like’ morphology evolved as a means of protecting most (but not all) of your seed crop. Could be experimentally tested.

In the last photo, have a gander at the super special growth form. Sprawling and with giant head-like inflorescences. Sort of makes you want to just give it a hug.

Wild collected, Namibia, Tripp & Dexter #833,  1990, & 1965 (RSA-POM); Photo by Erin Tripp

Wild collected, Namibia, Tripp, McDade & Dexter #4077 (RSA-POM); Photo by Erin Tripp

Special species!! Sort of like Special Sauce but WAY, way better! Just take my word for it!

First specialness: GROOTBERG MOUNTAINS. I need not say more. Best geology in the world. GO THERE.

Second specialness (competes for first): ACANTHACEAE PRODUCE SWEET FLORAL ODORS IN THE OLD WORLD. It is true – so very true! And I aim to get Rob Raguso and his awesomeness on this, as soon as I am able and have the funding to do so.

I first spotted this species from ~75 meters away, while flying down the (dirt, major) highway. As soon as I opened my door, we were met with a flush of intense, sweet jasmine-like odor. I took one look at a blazing ball of yellowness some distance away from me and knew immediately that (a) it was a Petalidium and (b) it was responsible for that amazing fragrance.

Note to the non-Acanth user community: this family of plants is basically known to be odorless. I was blown away by the discovery.

Petalidum giessii is extremely restricted in its distribution… more or less limited to a ~100 km stretch as far as we can tell. And it is completely distinctive – no doubt that it is a “good” species. Also little doubt that it is a close relative of Petalidium luteo-album, but… I have been wrong before. Once, I think.

First couple of photos: admire the Grootbergs and the plant.

Close-up of the corolla photo: in full glory…. you can practically smell it from your computer.

Yet another photo: in fruit from the previous season… rains hadn’t yet arrived…. photographed shortly before I was attacked by a leopard at dusk. Not kidding. Scar on lower right calf to prove it….

And finally: discover of a new population of this remarkable species, while exiting the depths of the remote Ugab River valley (May 2014, with Essie, Leevi, David, Josephina, and Iain).

Wild collected, Namibia, Tripp & Dexter #825 (RSA-POM); Photo by Erin Tripp

I haven’t a clue how to convey the coolness of this species to you. Petalidium englerianum was the very first in the genus to capture me (and shortly thereafter, Petalidium lucens — see that page). I saw it in the herbarium. Its leaves were bright white and begging for sunglasses owing to a thick indumentum of stellate trichomes. The species absolutely decorates the roadsides all around (but mostly north of) Windhoek. Very abundant, very impressive, and very important ecologically.

Its flowers, like so many other species in the genus, vary from uni- to bi-colored (see photo: four lobes sherbet orange and the dorsalmost lobe lemon yellow).

Another photo shows what a typical roadside habitat dominated by this species looks like. (You are not a farmer anywhere around Windhoek without knowing this species. It is THAT abundant.)

Additional photo shows Kyle probing one of the corollas for nectar. We then stick the goo into a refractometer to measure % sugar. Gives a pretty good idea of how lucky or unlucky the pollinators are..

Wild collected, Namibia, Tripp & Dexter #778 & 791 [and on numerous other occasions] (RSA-POM); Photos by Erin Tripp

Petalidium cymbiforme is arguably among the most unique species in the entire genus. It seems clearly related to other species in the “southern clade”, yet still very different. It also has an extremely limited geographic distribution. I’d love to have been around for its (evolutionary) birth… is it really recent? Why isn’t it more widespread? And WHY isn’t someone cultivating this plant? One of just a few species in the genus with stark white flowers. Perhaps the most beautiful of all.

Wild collected, Namibia, Tripp et al. #2078 (RSA-POM); Photo by Erin Tripp

Petalidium crispum commands so much more attention than these photos could ever convey! True to the epithet, its leaves are crisp and borderline NASTY pungent. Kyle and I first encountered this species during our first trip into Marienflüss… sometime around the magic hour… the scorching sun was thinking about sinking. To our tremendous delight, Petalidium crispum absolutely cloaked the lower cliffs of a bright red slope that reminded me, of all places, of the Mojave. The sunbirds didn’t seem to mind our presence and went about their business extracting good stuff from the corollas (see photo).

Much more to a point of *trying* to be serious (it’s hard, when life is so much FUN): there is an extremely interesting evolutionary story going on between Petalidium crispum and is presumed (almost certainly) sister species, Petalidium subcrispum. Ok — forget the ‘presumed’ bit – these two species are nearly identical except for their flowers. Red/bird/crispum and purple/bee/subcrispum. Most remarkable thing: they are nearly sympatric…separated only by the width of the valley (Marienflüss), which is at most a couple of miles wide. They flower concurrently. They have potential to exchange genetic material. So how do they maintain reproductive isolation (or.. do they?). We have a field experiment stewing…

PS 1: Glandular trichomes on calyx of Petalidium crispum become spiny and quite uncomfortable to the flesh when dry.

PS 2: The Himba use this plant as a perfume. Really? Yep – that’s what they told us (via Leevi, who can speak their language well enough). Celebrate diversity – the world is more interesting for it.

PS 3: I love the landscape photo – epitomizes the Kaoko (and Kyle): complete with the latter sitting down in the bottom of the wash looking like a tiny fly, but one with binocs watching birds…

Wild collected, Namibia, Tripp & Dexter #2005 (RSA-POM); Photos by Erin Tripp

Petalidium coccineum, I can still remember the first time your giant red flowers pulled our eyes from the highway and onto your gravelly shores. We saw you from quite the distance – all alone – but spectacular. Our first bird-pollinated Petalidium. Our lives will never be the same.

Wild collected, Namibia, Tripp & Dexter #843 (RSA-POM) [and on several other occasions]; Photos by Erin Tripp

The ever impressive Petalidium canescens always turns up in the most inhospitable of environments. I’m surprised it hasn’t reached the top of a tepui yet (well, not really). Here it is germinating in sun-fired roadside clay, in an environment so dry that it hurts to breathe–I am not kidding. This is a species to respect.

Petalidium canescens is emblematic of Damaraland in east-central Namibia. Very nice farmers have welcomed us onto their property to learn more about the natural history of this species.

Salute!

Wild collected, Namibia, Tripp & Dexter #882 (RSA-POM); Photo by Erin Tripp

Don’t be jealous just because evolution didn’t fare so well for you.

Petalidium bracteatum has it ALL figured out. On a bloody hot day while I was cruising along on the right (wrong) side of the 4×4 track, in the Kaokoveld, in a heat-induced stupor, Kyle and Lucinda simultaneously spotted this thing through their awesome Acanth spectacles. It was growing out of vertical cracks in cliffs very near to the Kunene River / Angola border. We have yet to encounter this remarkable species anywhere else. At this site, 100% of its fruits were severely predated by some specialist frugivore (damnit!). Seeing the species in the cellulose absolutely clears up any doubt that we may have ever had about its distinctiveness from Petalidium coccineum. Definitely different, although almost certainly related. Need ‘Next Generation’ sequence data, as it’s clear that Sanger Sequences aren’t going to cut it…

Wild collected, Namibia, Tripp et al. #4054 (RSA-POM); Photo by Erin Tripp

Dear Petalidium bracteatum, canescens, coccineum, crispum, cymbiforme, englerianum, giessii, halimoides, and all of the others,

I have cheated on you. I always said that you were my favorite, but the unexpected happened in May 2014 – I fell in love with someone else. I have tried to do my best to explain why, below, though I do not expect you to ever forgive me….

Petalidium angustitibum has to be among the top three most intriguing species in the genus (right now, it’s my #1). Like so many other species in the genus, it is a restricted-endemic in the truest sense of the phrase. I was fairly convinced we wouldn’t find it. We traveled 80 something kilometers through the sand-filled Kwoarib River… no road to speak of… in attempt to find elusive and mostly historical populations of this species.

We found it. The corolla tubes of this species—the longest of any Petalidium—and the very elongate inflorescences (again, the longest of any Petalidium) make this species one of the most distinctive \within the genus. Other observations: 32% nectar at 13:30. In full flower, but almost entirely absent fruits. Fruits that we did find were almost entirely predated. Iain managed to recover one inflorescence with several viable fruits, so there is hope for continued study of this species in cultivation.

Regarding the low fruit set: I cannot claim to know the real story, but not a single floral visitor was seen throughout the course of the day. Is it possible that such pollinators are no longer with these plants are? And if P. angustitibum is not capable of selfing, well then, that’s the end of the road for this species (as an aside, we are rooting for you!). Whatever the explanation is, one thing is certain: the species is locally dominant in its native environment–indeed, it’s one of only a few species of flowering plants alive in this barren landscape–but it’s native environment includes a very, very small stretch of planet Earth.

After turning to the north, we drove on another 50 km or so, and made camp in a very special valley at the mouth of the Ugab mountains. Again: one of the nicest campsites of my adult life. I have photos to prove it….and lucky you, I’ll even share a snapshot of the beauty (see photo of four of us, above).

Wild collected, Klaassen et al. (awaiting data from Essie [WIND & COLO]); Photos by E. Tripp