We have a few favorite camping spots in some very interesting borderland highlands just west of Nogales. The Atascosa Highlands comprise three small closely spaced mountain ranges on the United States and Mexico border just west of Nogales, the Tumacacori Mountains, the Atascosa Mountains and the Pajarito Mountains.

During one of our recent camping adventures we came upon a plant that hadn’t been seen in the area, a milkweed vine formally known as Matelea tristiflora. Some of our friends are working on that group of plants and this species is about to get a name change: Polystemma parvitriste. It was formerly only known in a few spots in the Patagonia Mountains in the US and more common in Sonora; it was suspected to be in the Atascosa highlands, and I guess we found it.

This milkweed vine is difficult to find because the leaves look so much like the very prevalent morning glory vines (Ipomoea spp.) which are everywhere.

This finding, along with the banner year for rain, inspired us to increase our time on the field, documenting the cast of characters that reside in various locations. We make painstaking lists, listing every single species we come across. If we happen to come across a species we don’t know, we take very good pictures, and identify later. These lists go into databases that are used by botanists and researchers. We also report any significant findings to various researchers—in the case of this milkweed vine, for example, we notified some of our friends: like Jack Dash (who is working on a flora of the Atascosa Mountains (he is also working on a documentary which you should look out for and if you are very interested in the project, toss him a few bucks to help him get it done). We also notified our friend Sue Carnahan who is working on various floras, including one for Santa Cruz County, and is working with another friend, botanist Mark Fishbein, on a paper describing the Matelea tristiflora plant in our area as a new species.

Our documentations also go to the Madrean Discovey Expeditions database which is a portal of SEINET created to serve as a gateway to distributed data resources of interest to the environmental research community within Arizona and New Mexico. The Madrean Discovery Expeditions also emphasizes/includes a lot of data from Mexico which was lacking somewhat before their efforts.

We did some of this work last year when we found some rare plants in the San Rafael grasslands (which form the headwaters of the Santa Cruz river): another rare milkweed (Asclepias uncialis) and a rare chocolate flower (Berlandiera monocephala) a cousin to the common chocolate flower we all use in landscapes.

Lately, we’ve increased our efforts for a few reasons. For one, we have some time, because it’s summer and a bit slower at the nursery. But also, this is a record year for rain, which is occurring after a year of record drought and heat. And it is something we love doing. The work is important. How can we advocate for species that we don’t know about? We should know all we can about what is left of these wild areas, who resides there, and keep track of how these species are doing with all the pressures upon them from development, and other economic activities.

This first trip into the Atascosa highlands had us literally breathless. The first thing we noticed as we were heading south, passing through Arivaca, was the endless fields of Arizona poppy (Kallstroemia grandiflora). This species is not actually a poppy, but in the creosote bush family (Zygophyllaceae). It resembles a poppy from the distance. On a normal monsoon year, you might see some on the roadsides, and in places where water collects a bit more. But this year, the grasslands were spotted with those famous orange flowers throughout all the hills, and up into the foothills—seemingly endless fields of Arizona poppies.

As we kept going deeper and deeper into the area, we noticed other unexpected population explosions. Plants like mala mujer (Cnidoscolus angustidens) and ragged nettlespurge (Jatropha macrorhiza) in a normal year will be found in a few groupings here and there—coincidentally both plants are in the same family, the Euphorbiaceae. This year, they are everywhere. And these aren’t just seedlings. These are plants that are 3-4’ tall, which suggests that their tubers have been underground all this time, just waiting for the right weather. Or perhaps they have been coming out of dormancy each year, but only growing a few inches tall and easily missed?

Mala Mujer (Cnidoscolus angustidens)

Raggedleaf Nettlespurge (Jatropha macrorhiza)

Back in the 1990s I had been trained by one of the great botanists, Richard Felger, to be very thorough when documenting plants in an area—he encouraged me to list every species, whether it was a weed or a common plant or a surprising find—all had to be documented. And he pressed upon me the importance of being accurate—if the plant group is a difficult group, do the work and know the differences. It will take a lot of work to live up to his standards. Some groups of plants are difficult, even for seasoned botanists. Some plant identifications require catching the species when they are fruiting, and looking at their seeds under a lens or microscope. I wish I could say I have a handle on all those difficult plant groups: families like the Boraginaceae or the Cyperaceae, but I still have work to do.

Richard Felger, in Mexico, making notes.

Richard passed away recently, early this year. Richard taught me more than anyone I know about botany. Perhaps that has also inspired me to hit the field more. But also, both Katy and I really enjoy being in the wilderness, getting to know organisms that few people pay attention to or know. We both love camping and waking up to monsoon rains pounding the tent in the middle of the evening. We love cooling off in the streams. We love encountering wildlife—getting a good look at a gila monster, or getting startled by a flush of quail.

Another surprise this year was the Mexican passionflower (Passiflora mexicana). In recent years we’d find only a few, small plants, hiding in some shrubs. This year, especially in the lower valleys between mountain ranges, they were prevalent. And you always smell them before you see them—some people think the flowers smell like mothballs, I sort of think they smell a bit like the breath of that friend you have who smokes too much marijuana, lives in his bus, and maybe doesn’t brush his teeth too much (maybe some tooth decay is involved).

Another plant in the Euphorbiaceae that we really love is the desert mountain manihot (Manihot angustiloba). We found just a few plants off the roadside. When we first found them at first, they were quite lush. This is a tropical relic—most of the genus resides south of the border. There are many species of manihot but we only have a few species in Arizona, and only hiding in the rocky microclimates of our southernmost mountain ranges.

To anyone who may have lived in the American tropics, the foliage may remind you of tapioca plant (Manihot esculenta) of which this species is related. But I don’t think it is used in the same way. Most plants in the family are poisonous, with only a few that are actually edible.

The three plants in the Euphorbiaceae, spurge family, that we’ve so far discussed, the nettleleaf ragged spurge (Jatropha macrorhiza), mala mujer (Cnidoscolus angustidens) and desert mountain manihot (Manihot angustiloba) have also been seemingly disappearing as quickly as they emerged. But it’s nothing to be alarmed about—they are being eaten by the larvae of moths, especially spinx moths. We especially saw many larvae of the ello sphinx moth (Erinnyis ello).

This mala mujer was quickly turned into stems by the ello moth larvae. But no worries, this plant has evolved with this sort of herbivory and will re-sprout from the tuberous roots. Lush years for plants means lush years for insects.

The arizona passionflower (Passiflora arizonica) may not have smelly flowers, but it has carnivorous ones! Recently, it was discovered that the sticky bracts that surround the flowers and fruits of the stinking passionflower (Passiflora foetida, which is only really smelly when you crush the leaves) aren’t just sticky for no reason. Tiny little gnats and other small insects get stuck to these sticky glands. And most recently it was discovered that these plants have organs that can accept the resulting nutrition from the dead and decaying insects. Arizona passionflower is closely related to this species, and has similar sticky bracts. This year, as with many other plants, we noticed a lot more Arizona passionflower than in previous years.

Another plant that has been showing off is the long-leaf morning glory (Ipomoea longifolia). This plant is very different than more weedy species of Ipomoea, and it should be noted that the genus gets a bad rap because of a few species. Most native species of Ipomoea are well-behaved.

This plant is more likely to be found sprawling across the ground rather than vining all over shrubs, though it is capable of doing some proper vining. The leaves are huge, and long (as the name denotes). And the flowers are probably the most magnificent in the genus.

We really have to pay attention. Some of the plants are very tiny. Somehow I spotted this plant, though we were driving. It is the tiniest little thing, but very beautiful when you inspect it closely. It might remind you of something in the pea family (Fabaceae) but it is in the milkwort family (Polygalaceae). This little-known plant is the tropical milkwort (Polygala glochidatus). It’s only been recorded a few times in the US, and has been recorded from the Atascosa highlands before. But its a wonderful little plant. These are the sorts of finds that we really love. These organisms are out there, living out their lives, and almost never noticed. This plant won’t ever be anything that would be in cultivation—it’s too small and it’s an annual. But it can be appreciated in its wild habitat if we allow it to exist.

We encountered almost nobody the entire time we were out in these remote places—we did get accosted by a border patrol helicopter once. It was creepy being hovered over while some guy stared at us with his legs dangling out the side, like he was in Vietnam or something.

It rained on us a few times (we didn’t mind the rain at all, and were fairly prepared). The insects were a bit bothersome, but we’d rather be bothered by insects than have a world without them. Last year’s lack of insects was very worrisome. This year we spotted numerous moths, butterflies, and many other insects. The birds were making us crazy too; we kept seeing what we knew were cool birds. But it is difficult to be botanizing, paying attention to plants, and also paying attention to birds. “Another time”, we kept telling them as they flew over our heads, taunting us to try to identify them.

We camped out in a few spots, mostly at an old hippie homestead where some remaining domestic trees persist—we pitch our tent under a big mulberry.

We can’t possibly share all the images we have of our excursions into the Atascosa highlands, but here are a few random images—it takes a lot of time to transfer the image to the computer and export it as a size more appropriate for the web, so the following selection of images is somewhat random and just a small sampling of what we’ve documented.