Hooked on Trichomes … The Curious Nature of ‘Mentzelia’

July 29, 2025

You must awake when the first rooster crows to enjoy the floral beauty of a fully flaired Blazingstar blossom. Appropriately named, these gorgeous flowers display a radiant combination of spoon-shaped petals, petal-like stamens, and hundreds of thread-like stamens, all colored in bold sulfur yellows, distinctive pale orange-yellows, brilliant star whites, or fluorescent blues, based on species.  These superbly showy flowers unfurl overnight atop tall white, branching stems that resemble candelabras with narrow lobed green leaves. These large, 2” diameter flowers belong to the Mentzelia genus, plants that are all native to the Americas, and represented by 60-80 species, most found in the desert southwest. 

In 1753, Carl Linneaus gave this plant its genus name, Mentzelia, after German botanist and sinologist Christian Mentzel. (Did you know a Sinologist is a specialist in the study of Chinese language, literature, and civilization? Huh!) But perhaps more fascinating and what’s always ‘captured’ my complete attention (and blue jeans) is that the Mentzelia genus fits perfectly in the Loasaceae family ….. commonly referred to as the Stickleafs

About those leaves …… 

Being primarily a day-time hiker, my first encounter with a Blazingstar occurred simultaneously with a misstep into the plant. Noticing some resistance in making my escape, I looked down at the ground and discovered my jeans had a collection of stuck leaves from my boots on up. And the leaves were really stuck tight along their entire length! Removing those leaves was like peeling a banana, only tougher. Wait! Forget the banana peel. Removing those sticky leaves sounded like and felt like tugging on and separating Velcro! I was reminded of the familiar ‘ripping’ noise made when Velcro hooks are forcibly released from their loops!

Eureka!!

Nature is full of surprises. Were the Stickleafs the source of accidental inspiration for today’s handy hook-n-loop fastener, called Velcro? Almost, but not quite! As it turns out, the tiny hooks on Cocklebur seedpods inspired a Swiss engineer to develop Velcro in 1941. But not to change subjects too much …….The reasons Stickleafs could’ve been the inspiration for Velcro, is similar to the Cocklebur story, but, I think, even better. Here’s why …… 

The seedpods of both plants have tiny hooks that readily adhere to clothing and fur. And it was the hooks’ tenacity for stick-to-it-tiv-ness that grew the original Velcro idea. But Stickleafs go even further in ‘reinforcing’ the fastener concept. Not only does the seed pod (capsule) of Stickleafs have a covering of tiny hooks, but both leaf surfaces and even the stems of plants in this family can have multiple types of minuscule grappling-hooks and barbed needles, called Trichomes, visible only with an electron microscope. I summarize that if the Swiss engineer was visiting America in 1941, and had the good fortune to walk into a Mentzelia plant, he undoubtedly would’ve been super inspired to develop Velcro. After all, it’s the leaves that stick fast to clothing, resemble a strip of Velcro, and hold tight, mimicking an ideal hook-n-loop fastener.

Hooked on Trichomes 

And now for the curious nature of the Mentzelia genus. When coming across the Adonis Blazingstar (Mentzelia multiflora) over the past 8 years, it’s been fun to inspect the leaves, remove one and intentionally stick it to Roy’s jeans or mine. I’ve then wondered how this plant ‘sticks’ so well, and why. The time for answers arrived this month, and what I learned was fascinating.  It’s all about Trichomes.

Trichome is a botanical term used to describe the small hair-like structures that occur somewhere on a plant; typically on plant leaves. Trichomes can be found throughout the plant kingdom (like on Cannabis sativa); they aren’t unique to the Stickleaf family, and are found on all species of the the Mentzelia genus. Some Mentzelia species have one type or shape of trichome; some have several types. Adonis Blazingstar has two types of trichomes – one is shaped like a grappling hook; one is shaped like a barbed needle. It’s the trichomes that grab on and hold tight. But what possible function do they serve the plant? Surely a leaf sticking to the fur of a passing animal or a person’s pant leg, while decorative, is otherwise pointless?

What Good are Mentzelia Trichomes?

Like plant hairs, trichomes aid a plant in water conservation in times of drought by reducing transpiration, and in situations of other environmental stressors, such as excessive UV light and extreme temperatures. The trichomes serve as a protective barrier between the leaf, stem, or other part of the plant, and the environment.

Trichomes can function as water collection, retention and funneling structures during a rainstorm. 

The grab-and-hold nature of trichomes when they attach to fur or clothing can cause enough vibration of mature seed capsules to shake loose seeds ready for dispersal.

Trichomes are the plant’s primary defense against herbivory; not from livestock or rodents intent on munching leaves, but from insects that attempt crawling amongst the grappling hooks and barbed needles intent on causing damage. As can be seen in electron microscope images, insects have been photographed speared and hooked and killed because they were unable to escape their entrapment by trichomes. 

But not all insects succumb to the fate of trichomes. Aphids are able to navigate the dense forest of hooks and needles without capture, allowing them to wreak havoc on vulnerable and tasty leaves, stems and seed capsules.  

And that’s why the Mentzelia genus of the Stickleaf family is one of the natural curiosities of the plant kingdom. Maybe now, you too, are Hooked on Trichomes?

I hope you’ve enjoyed this post, and do thank you for stopping by!

And if you’re curious about how Trichomes contribute to the enjoyment and/or medicinal benefits of marijuana (Cannabis sativa), here’s what I found:

Trichomes are the primary site for cannabinoid production (i.e. compounds like THC & CBD responsible for the plant’s psychoactive/therapeutic effects.

Trichomes are the site of terpene production which gives different Cannabis strains their unique aromas/flavors.

Trichomes are the site of flavonoids known for antioxidant and medicinal properties.

Winter Botany: Horsetail Milkweed

February 1, 2025

Wandering about the neighborhood one warm summer morning in 2018, I noticed a dense stand of plants lining a 20 foot section of road. What caught my eye were the umbrella-like clusters of pearly white flowers topping each slender stem. From a distance these plants resembled our native white-flowering yarrow. But I soon realized the narrow dark green leaves were not fuzzy; the tiny exotic-looking flowers were not daisy shaped. Unmistakably, this plant was a species of milkweed! And the flowers of more than 50 individual plants in this population were a-flutter and a-buzz and a-crawling with hungry insects!

What was this milkweed species?

This is the Winter Botany portion of this post. All that remains of last summer’s Horsetail Milkweed are stems and mostly empty seed pods clinging to short branches. But some of the seed pods still hold silky tailed seeds clinging to their open pods. Hundreds of seed pods line the roadways in our neighborhood.

It didn’t take long to confirm this plant as Horsetail Milkweed (Asclepias subverticillata), a species commonly found along roadsides in pinyon-juniper woodlands. Knowing what to look for on future walks, over the next several years I was excited to find 30+ more populations of various sizes along neighborhood roadways! From 2018 until early summer 2024, I continued to monitor these seemingly abundant populations. The small numbers of seeds I collected in the Fall were planted in our yard, and every year I checked for the presence, variety and numbers of insects busy feeding on nectar as they pollinated the flowers.  

During June 2024, when we moved only a few miles to the northeast, I was happy to see Horsetail Milkweed grew abundantly in our new subdivision. This prompted me to dig deeper into researching this species. Its been exciting to discover how important this milkweed is to native insects, including monarch and queen butterflies.

Photo (mine) taken in July 2022 of a blooming Horsetail Milkweed being enjoyed by a feeding wasp.

According to pollination ecologists, Horsetail Milkweed is especially valuable to large numbers of native bees. This plant species also supports conservation biological control by attracting predatory or parasitoid insects that prey upon pest insects. 

And Horsetail Milkweed is one of the favorite host plants for monarch and queen butterflies, all because it’s toxic!  Producing an especially nasty tasting and potent neurotoxin strong enough to kill livestock, the caterpillars of these two butterflies have evolved to benefit from such a poisonous substance. Voraciously ingesting a diet of only milkweed leaves, obviously tasty to the larvae, makes them unpalatable to would-be predators, such as birds. The toxin from milkweed leaves has become their primary means of defense; definitely a benefit for such chubby, slow little caterpillars.

Monarch caterpillar (source: open commons)

Although central New Mexico isn’t in any of the major migratory routes of these butterflies, I have observed both species in our previous neighborhood. Since learning more about Horsetail Milkweed and it’s favored roadside habitat close to home, my hope is to provide actively growing plants throughout the summer (a safe distance away from roadside easements) for both the monarch and queen adult butterflies and their caterpillars ……. especially important when governing covenants of our previous and new subdivisions require the roadways be groomed (mowed down like a butch haircut!) on a monthly basis by subdivision landscape crews. 

Because milkweeds are among my favorite of all plant species, mainly due to their complex flowers and the clever trickery they’ve developed to ensure pollination, I wrote about and illustrated two in-depth blog posts on this subject. Believe me when I say,  “It’s overboard fascinating!”

Check out the following posts …..

Surprise! A vine-y, twine-y desert milkweed discovery from July 2024, where I revisit milkweed flower structure and pollination and learn about a new-to-me genus, Funastrum.

Summer Botany: Meet the Milkweeds from July 2022. This is my first comprehensive look at milkweed flower structure, how pollination takes place, and the genus Asclepias.

Read on to learn more botanical information about Horsetail Milkweed AND how to find out if you live in Spring and/or the Fall Migration routes of the monarch butterfly AND where queen butterflies migrate to and from. 

Characteristics and habitat requirements of Horsetail Milkweed

Horsetail Milkweed is a perennial species with a stout, woody rootstock. Plants readily spread by rhizomes (underground stems) producing dense communities. Cold-hardy to at least 0℉, this milkweed bounces right back in the Spring. Plants are also drought-tolerant once established, thriving in well-drained, sandy soil under full to partial sun.

Able to thrive in a variety of habitats and plant communities from 2500 – 8000 feet in elevation, Horsetail Milkweed grows among grasses, on sandy or rocky flats, on slopes, roadsides, and along trails in Chaparral, Semidesert Grasslands, Pinyon-Juniper Woodlands, Montane Conifer Forests, and in disturbed areas.

All of these characteristics and its adaptability to a wide range of habitats make Horsetail Milkweed one of the easiest milkweed species to grow.

Monarch butterfly (source: open commons)

Monarch Butterfly

To learn if you live within the path of or close to spring and/or fall monarch butterfly migration routes, you can view a map or these route here:

https://www.monarchwatch.org/

Queen butterfly (source: open commons)

Queen Butterfly

The queen is chiefly a tropical species. In the US, it is usually confined to the southern portion of the country. It can be found regularly in peninsular Florida and southern Georgia, as well as in the southern portions of Texas, New Mexico, Arizona, and California. Occasionally, the subspecies of the queen can be found somewhat north, in Kansas, Colorado and Utah. 

Queen butterflies do not migrate as dramatically as monarch butterflies, but they do move short distances in tropical regions with dry seasons to higher elevations.

Queen caterpillar (source: open commons)

As always, thanks for stopping by!