"She ran her hand down my goldenrod, feeling for pubescence..."
Hey dirty mind! Being a botanist is sensual. But sometimes not in that way.
She's differentiating Solidago species in the canadensis complex.
When we encounter plants, we do so with our animal senses. This is how we ask plants their names, their niche, their medicine. Smelling, rubbing, tasting. Squinting for a glaucous bloom or a fine puberulence. When we do this, we connect with the very foundations of our wild sensuousness. Because a big part of the reason we have senses in the first place is to know the plants.
Sometimes people ask me to recommend apps that identify plants for you. First, this is a bit like asking John Henry for a brand recommendation on a steam engine, so f/ck off. Second, there's a difference between data and real experience. Data you download into your coconut, and you're lucky if you remember it enough to parrot it back next time you want to look like an expert. Experience shapes you. Remakes your senses. Causes you to fall in love. Grows new connections in your brain pathways.
The point being, botany is basic, primal stuff, we can all do it, and it might even improve your sex life (yes Google that's a keyword). If you can go to the supermarket and tell the difference between a nectarine and a peach, you're a damn good taxonomist who can make subtle distinctions between glabrous and tomentose fruits. Take this skill set to the wild and your sensuousness will only grow.
Take my hand, let's take a walk on the wild side. We can identify plants, discern habitat preferences, and intuit medicinal properties... using our five senses.
We're so programmed to be a set of eyeballs connected to a screen via our fingertips, maybe we don't think of smell that often. Other animals are rather famously better at it than we are. Still, after sight, this is probably the most used sense in doing field identification. It's also an important precursor to taste, reaching the brain with sufficient speed to allow us to shut the gate on whatever we were just about to eat if the nose says no.
Mints are a classic plant family to identify by scent (usually confirming an ID based on square stems, opposite leaves, and tubular flowers). The scent of wild species ranges from the thyme end of the spectrum (thymol being the dominant chemical marker) to the spearmint end (menthol), with stops along the way for other constituents such as geraniol (rosey, citrusey) and linalool (lavender-scented).
These diverse minty phytochemicals are what confers herb status on so many members of the mint family, from peppermint to basil to rosemary to bee balm. They add intrigue to our food, and have medicinal actions in our bodies. The chemicals we smell when we crush a leaf are volatile oils (they volatilize at a temperature below the boiling point of water). Why would a plant generate chemicals that volatilize when leaf tissue is crushed? That's right, they are pest deterrents and contact antimicrobials. Plants don't have immune systems but they have a killer chemical armament. And since we're not so different from them, these plants become medicine when we have issues with bacteria, viruses, fungus, and parasites.
Some field applications of smell:
Distinguishing black cherry (Prunus serotina) from black birch (Betula lenta). These two tree species have similar silvery lenticular bark when young, and fairly anonymous leaves. People have a hard time distinguishing these visually. But scratch some twig bark with your fingernail until you see green beneath. Cherry species have a powerful almond scent, intoxicating and cyanide-like. Black birch has a wintergreen aroma. Black cherry's medicine is to sedate heat. Birch's is to refresh and release. They are easy to tell if you use the smell.
Lily-of-the-valley vs. ramps. Two monocots with similar leaves. One is a gourmet edible, the other contains high levels of cardiac glycosides. One is native, the other a garden escape. Easiest way to tell the difference? Smell. Ramps (Allium tricoccum) have a distinctive onion family fragrance, a juicy, garlicky zing. Rip off a chunk of leaf and test it with your nose before anything goes in your harvest basket!
Scene: springtime botanical survey. We find a mysterious set of basal leaves in the woods. We pretty much know it's a composite, but is it an unusual aster... or a goldenrod? Tear a piece of leaf. Goldenrods have a sharp terpene scent. It's part of what confers deer and pest resistance to members of the genus. I can't describe its bouquet, but it's sharp and cutting the way citrus is. Next time you pass a goldenrod, give it a try.
Also smelly: Tree-of-heaven (Ailanthus altissima), when cut, smells like rancid peanut butter. This signals our body to the toxins found within, and helps differentiate young sprouts from sumac and black walnut. Siebold's viburnum (Viburnum sieboldii), an emerging invasive species in rich shade, has foliage that smells like rancid green peppers.
Your eyes are doing one thing, but your hands could be doing something else. Like scooping a handful of golden Indian grass seeds off their stalk in a tall meadow while your eyes follow the lilting flight of a goldfinch (the former being a very satisfying thing for hands to do, you should try it.) We assume a plant identification with our eyes, but often touch can confirm it. As in white snakeroot versus stinging nettles, both with similar opposite leaf arrangement and leaf shape. One poisonous, the other edible. Very different hand feel. Or, less painfully, to identify slippery elm (Ulmus rubra). You can surely eyeball it, but the way to tell for sure (and one character for distinguishing it from American elm) is to rub the leaf. Slippery elm is sandpapery (scabrous) like a cat's tongue.
Some (other) field applications of touch:
Just lick it: Karl Anderson, an elder botanist and mentor of sorts, once told me how he distinguishes Polygonatum pubescens from Polygonatum biflorum. That's smooth Solomon's seal and hairy Solomon's seal. The latter has fine, tiny hairs on the underside of the leaf, the former is glaucous. Hard for older eyes to tell. What does Karl do? He licks the underside of the leaf. His tongue, not nearly as leathery as the rest of him apparently, easily discerns the minutely pilose hairiness. For the record, Karl also pulled a shard of glass out of his Crocs using his teeth along the side of the road in the Pine Barrens. Just saying. The old botanists are tough, in addition to being sensual of course.
Two maples. One will give you syrup, the other is a pain in the ass. I'm referring to the delicious sugar maple (Acer saccharum) vs. the invasive Norway maple. Both have large, untoothed, lobed leaves. A good trick to distinguish them is to pull off a leaf at its base where it meets the branch, and squeeze the point of attachment (i.e. the end of the leaf stem). The sap of Norway maple runs milky white, sugar maple's is clear. However... what if it's wintertime and you have no leaves? Younger trees of both species have variable bark, sometimes quite smooth. Best way to tell is the dormant terminal bud. Sharp in sugar maple, blunt in Norways. Hard to see sometimes, but poke the pad of your fingertip with one. You've got sugar maple if it feels sharp and needlelike.
We discussed, back in smell, how using your nose is an important precursor to putting something in your mouth. Something that might be rotten, or... misidentified. Taste is usually not a good place to start the ID process. But it can provide confirmation once you already know the answer. Go ahead and taste the mountain mints, wild bergamots, wild leeks, goldenrods, and black birches... once you've 99% sure identified them already. The more pathways to the brain you lay out, the more likely an experience will come to reside in your long-term memory. Like Proust and his darn madeleine.
Our tongue (and nose, too) is basically a small chemical detection lab at an important orifice in our body. For example, we can taste denatonium, the bitterest known substance, at 0.05 parts per million. This goes beyond just simple plant ID - figuring out something's name - to really getting to know the plant.
Contemporary herbalists use taste as a way to characterize and determine medicinal properties. Our Deep Time ancestors did this too, I'd wager. An easy example is astringency. It makes the tongue feel dry and puckery. This is a characteristic of species as diverse as witch hazel, oaks, persimmons, and unripe bananas. Astringency helps to tone and constrict tissue. Remember what astringency did to your tongue? That's what witch hazel does to your butt hole if you have hemorrhoids, and that is a very good thing.
Other tastes: Bitterness stimulates digestive secretion, found in herbs such as gentian, goldenseal, and dandelion. Heat, found most notably in herbs such as cayenne and various mustards, is a mover, a stimulant, and sometimes a good catalyst.
Here's a tale of two cousins, the Monardas.
One is fiery and sharp, the other cooling and gentle. I speak of wild bergamot (Monarda fistulosa) and bee balm (Monarda didyma). Wild bergamot has a radishy heat to its foliage, and sharp thyme flavor. It grows in dry, sunny, gravelly terrain. Medicinally, it is used as an antiseptic, for burns, against yeast and fungus, and for "corpse sickness". Meanwhile, bee balm is as its name would suggest. It has a lovely rose-citrus flavor, and grows in moist, rich soils partially shielded from sun. It is soothing and treats stomach distress, especially stemming from anxiety. Taste reveals a bit about the habitat and personality of each.
OK, I saved sight until later because it's the obvious one. Anyone who has used Newcomb's Wildflower Guide knows the three sacred questions, pertaining to floral type, leaf arrangement, and leaf shape. Does it look like a daisy or a snapdragon? Are the leaves attached directly opposite one another, or alternate? Etc. These are key diagnostics and you should start with them before anything else. But let's take it a step further. Sight can help us name plants, but it can also help us to deduce who the plant is pollinated by, and what its habitat is.
Pollination syndromes. Why the dreary name, I don't know. It means: different kinds of pollinators use different kinds of flowers, which are often either evolved for a specialist pollinator, or for all access. Not only does this mean that flowers which have evolved to be pollinated by hummingbirds are long and tubular with a nectar reward sited at the terminus of where the bird's bill can penetrate, but it also means that flowers that are preferentially pollinated by hummingbirds tend to be red, because birds see the color red vividly. Hence cardinal flower, bee balm, and wild columbine. If you've ever seen a European columbine, it's not red and its corollas are not nearly as long. Why? Because hummingbirds are restricted to the Americas. Similarly, bumblebee plants tend to have blue flowers (tubular, but shorter than hummingbird flowers). Examples include bottle gentian and great blue lobelia. And moth-pollinated flowers tend to be white -- because white shows most vividly in the moonlight when many moth species are active.
Xeric habitats. What passes for xeric habitats up here in the Northeast are generally either glacially-scoured ridgelines or sandy coastal areas. Plants in both places (some are held in common, like our native prickly-pear cactus) are often diminutive "stress tolerators": they are perhaps more adapted to survive heat and desiccation than to compete with each other. I remember crouching over a small patch of glade flora at Jenny Jump State Forest, on thin soil over bedrock. Most of the plants were small, several had leaf adaptations to avoid moisture loss. There was rattlesnake weed (Hieracium venosum), with nary a stem leaf and instead basal leaves hugging the ground, where wind is stillest. Its beautifully purple-marbled leaves are also covered in long white hairs, probably a mechanism to reflect sun and/or preserve moisture. Orangegrass (Hypericum gentianoides), another diminutive species, had needle-like appressed scaly leaves, with minimal surface-area-to-volume ratio and thus less moisture loss. Even the resident mountain mint, hoary mountain mint (Pycnanthemum incanum) is covered in fine white downiness, presumably to retain a humid zone around its photosynthetic tissues.
Also weird-looking: the emerging invasive Amur cork tree (Phellodendron amurense) has no terminal buds on its branches. It looks like an ash, with opposite buds, but nothing in the middle, just a smooth area, at the end of the branch. Like Barbie's crotch (or Ken's, you choose). Also, the inner bark is fluorescent yellow, cut off a swatch of the corky stuff with your knife and it will blaze forth from beneath.
I won't make up some b.s. about the wind in the willows. What I will say about hearing is this. Go out to your favorite wild spot. Gate off your other senses, and just listen. Doing this midsummer when the heat bugs are shimmering is optimal. You will become aware of a three dimensional soundscape. Their vibrations come in waves, oscillating through the woods. Hearing locates movement in 3D all around our bodies. It's not so much for identifying wildflowers as it is for saving your ass while you've got your nose in a rose. Listen for the footfall of a mammalian predator, the buzz of a yellow jacket monitoring activity by its hive, or the rustle of a snake in the leaf litter. Anticipate the arrival of yahoos on foot minutes ahead of time, and yahoos on ATVs from a mile away.
BE A SENSUAL BOTANIST
When I teach about wild edibles, people inevitably ask about the poisonous plants. Now, there are not that many really fatal species in our flora, but they serve a really important purpose. Lots of us are interested in foraging, in free food, in reconnecting. The poisonous plants are the ones that will make you a damn good botanist. Because anyone with sense is going to work out an ID from a few angles before trying something new. Just in case.
Not far back in hominid history, our ancestors (sometimes even our grandparents depending where you come from) ate over a hundred species of plants and may have used several hundred for medicine. We all knew how to identify food, "on the branch". Our senses were our birthright, allowing us to consume sweet wild strawberries in June and rich groundnuts in October. Our senses help us to identify and also to take pleasure in these foods. What would food be without taste?
So hone your senses, and hone your pleasure. Be a sensual botanist.
 "The Quantum Limits of Human Senses, and Other Cool-Sounding Crap", retrieved from http://timeblimp.com/?page_id=894 on 5/10/2018.
 This section owes much to herbalist Jim Macdonald. See for example, his article "Blessed Bitters": http://www.herbcraft.org/bitters.pdf
 For a fantastic treatment of this plant with lots of good stories, see Matthew Wood's Book of Herbal Wisdom. A generic title for a singular and fascinating text.