Monday, June 24, 2013

Joseph Lord, a new 18th-century buddy

When I was in London a couple of weeks ago, I spent a day at the Natural History Museum, photographing a few more collections from the Sloane Herbarium. I had found three collectors we'd missed with our first round of photography. They are Joseph Lord, Col. Halsteed, and George Franklin - three guys who were in South Carolina between 1700 and 1710. That makes them the earliest collections we've worked with so far.

Joseph Lord is by far the most important of these three. Lord was a true American, born in Massachusetts in 1672 and educated at Harvard, after which he became a minister. (Did anyone from Massachusetts become anything else?) In 1695, Lord took a group of parishioners to South Carolina and founded the town of Dorchester. He built a house there and developed a plantation, which he mentions repeatedly in the notes to his plant collection.

Ah, yes, the plant collection! And the notes! Lord made his plant collection in 1704, and sent it to London to James Petiver, an apothecary who assembled a number of the collections in the Sloane. Lord's handwriting is beautifully legible, and he recorded useful details - things like color of flowers (a detail that is lacking in many herbarium specimens, which tend to be shades of brown), growing conditions, type of soil, and collection date. Patrick has already made good use of Lord's notes in the determinations we've begun.

We've already found something super cool - a specimen of Schwalbea americana, American Chaffseed, in the lower right corner of H.S. 158 f. 245.This is almost certainly the first collection of this plant, which is now in danger of dying out completely. This plant was listed as a federally endangered species in 1995.

American chaffseed is native to the longleaf pine ecosystem. It's a hemiparasite, or partial parasite - it performs some photosynthesis on its own but gets some of its nutrients and water by attaching itself to host plants with specialized roots called haustoria. It's not particular about hosts - American chaffseed parasitizes longleaf pines, hollies, and various grasses and composites. It's a fire-adapted species that depends on periodic fires to clear out vegetation to allow seeds to germinate and seedlings to establish themselves. Fires were regular occurrences in the longleaf pine savanna that was common in South Carolina before European settlement, but that has nearly disappeared from the region today.

This is one of the rarest plants on earth today. The 2008 5-year review noted 33 occurrences in South Carolina, 12 of which were considered protected but none with formal protection agreements and only one with a formal management plan. Almost all occurrences were in the Francis Marion National Forest. Total numbers had dropped between 1995 and 2008; and remember, those 2008 numbers are based on surveys done prior to 2008. So we don't really know how many of these plants are left. Some of these areas are being managed with controlled burns, which benefits a whole range of fire-adapted species. But there's not much space for them, and small populations are prone to getting smaller.

So it's neat that Lord picked an American chaffseed.

Wednesday, May 15, 2013

An introduced invasive - in 1710

Patrick and I have gone through some of John Lawson's specimens - so far we've done determinations on his specimens in H.S. 158 and H.S. 145. These are intriguing because they were collected in 1710 or earlier (couldn't have been later, because Lawson was killed by Indians in 1711 - more on that in a bit). That was long before major European settlement in the Carolinas, more than a decade earlier than Mark Catesby. Lawson wrote a really great book about his adventures, A New Voyage to Carolina, which describes his fun with native Americans after most of them had died from smallpox but before they disappeared as a significant social force in the area. (Many thanks to UNC for digitizing this book!)

Anyway, Lawson was kicking around the Carolinas EARLY. The Lords Proprietors didn't get going with the Province of Carolina until 1663. Charleston, SC was founded in 1670. (This would be a great time to review my Restoration history - you known, when Charles II took the monarchy back in the wake of Oliver Cromwell's death.) Lawson set out for the Carolinas as an explorer, mainly because he heard that Carolina was the best place to go, and spent the next decade traveling around the countryside. His writing displays enthusiasm for his surroundings, keen observation of both natural history and human interactions, and a good sense of humor at said interactions. Also, his descriptions of animals combine observations on their physique and behavior with culinary notes. His book was a bestseller in Europe and persuaded many would-be settlers to follow Lawson into the wilds of Carolina.

Because Carolina was still wild when Lawson was there. There were some settlements, and some farms, but much of his food on his journey came from native Americans who were hunting and gathering wild foods. Not many Europeans had yet arrived in this area.

So imagine my surprise to find a specimen of Rumex crispus, curly dock, in his collection! (It's on H.S. 145 f. 62.) He (or someone) even wrote a note on it - "Wild dock a sorrell, Trout River June 20th 1710, vid with Leed[?]"(Lawson's handwriting is a bit difficult for me to decipher. "Vid" means "saw", and I think he is saying that he saw this plant with a man named Leed, or perhaps Lord.) The remark about "sorrell" is correct, as all the members of the genus Rumex are commonly called docks or sorrels.

This plant is native to Eurasia. It's currently present in every state in the U.S., and most of the world too. North Carolina now considers it one of the most troublesome invasive weeds in the state. The seeds get into agricultural seeds and they stick to clothing. So how did the darn thing get to the Trout River by 1710? Did some Englishman go walking in the countryside and then board a ship without washing his trousers? Did someone carefully save some seeds to plant in the New World, as a healthful taste of home?

In any case, that sure was fast. People move, and plants go with.

Catesby collected a bunch of introduced plants 13 years after Lawson. In a couple of weeks I'm going to the Sloane to photograph more plants collected between 1700 and 1710. We shall see how much of old Europe had managed to establish itself in North America by that point.

Oh, Lawson's death? Well, in his own book, Lawson describes a method of torture used by Indians in which they would stick a victim full of pine splinters and then set him on fire, to dance to their delight. Lawson was captured by the Tuscorora Indians in 1711 and apparently put to death, though no one knows exactly how this occurred. Lawson's friend Christopher Gale claimed that he died according to the pattern he had himself described. Qui sait?



Wednesday, May 8, 2013

Animals in the Herbarium

If you've ever been snorkling or scuba diving in the Caribbean, you will have noticed waving fields of things that look for all the world like plants. They grow out of the sandy or coral bottom, they are branched, and they sway gracefully in the current.

Plants they are not, though. You are looking at animals called gorgonians, also known as sea fans or sea whips. They're related to coral. (Sorry for citing to Wikipedia. Wikipedia is a good reference!)

What makes them animals and not plants? Among other things, they can't make their own food. They have to catch plankton and eat that. (Actually, lots of gorgonians do have symbiotic relationships with photosynthetic algae that produce some food for them, but in no sense are gorgonians plants.)

When Mark Catesby visited the Bahamas, he had no way of knowing that the sea fans he saw were not plants. They sure look plant-like! So he collected a gorgonian, and sent it off to London with his other herbarium specimens. That is why there are animals in his herbarium at Oxford.

Introduced Plants - circa 1723


Introduced species are a big deal in ecology. Species move around all the time, of course, but natural evolution tends to be slow and gradual. Plant species that evolve in a place are adapted to the local environment, and while the "balance of nature" is something of a myth, slow evolution makes for more stability. Introduced species appear abruptly, without slowly accommodating to the denizens already in place. Introductions may run roughshod over the local inhabitants because they aren't vulnerable to the general threats - these introduced species can become invasive. Humans have introduced species all over the world, both deliberately and accidentally. The process of introduction really took off in the 17th and 18th centuries, as Europeans sailed all over the globe and carried plant materials back with them.

But how can you tell if a species is introduced? How do you know when an introduction occurred?

Charleston, South Carolina, was founded in 1670. By 1690 it had become one of the five largest cities in the colonies. It was a major port and a hub of trade between the American colonies and the Atlantic. Ships arrived in Charleston from many locations. Ships arriving from Africa brought slaves. Ships from England and the rest of Europe brought settlers and manufactured goods. Ships from the Caribbean and South America would also have stopped in at Charleston.

Mark Catesby visited Carolina in the period between creation of the crown colony of Carolina in 1719 and the separation of South Carolina from North Carolina in 1729. He arrived fifty years after Charleston was established, and after decades of transit and trade had moved around myriad plants and animals, but BEFORE extensive European settlement of the area. The plants he collected thus contain a snapshot of the botany of the region early in the colonization process. Most of his collections are native species, but some introductions had already arrived.

The following species in Catesby's collections are all considered to be introduced or possibly introduced to the Carolinas (per Alan Weakley):
Dysphania ambrosioides (Linnaeus) Mosyakin & Clemants        00087426R
Gaillardia pulchella Fougeroux var. pulchella        00087294U, Sher-1957
Helianthus debilis Nuttall    Sher-1944-2
Stokesia laevis (Hill) Greene            Sher-1641
Tarenaya hassleriana (Chodat) H.H. Iltis = Cleome hassleriana Chodat            00087297X
Ipomoea coccinea L.  H.S. 232 f.61
Jacquemontia tamnifolia (Linnaeus) Grisebach    00087560Q, Sher-0359
Momordica charantia L.        Sher-2195
Croton glandulosus Linnaeus var. septentrionalis Müller of Aargau      Sher-2069
Indigofera tinctoria L.           H.S. 232 f.106
Mimosa quadrivalvis L.         H.S. 232 f.107
Senna occidentalis (L.) Link             H.S. 212 f.1, H.S. 212 f.81
Nepeta cataria L.       00087449W
Prunella vulgaris L.   00087454S
Modiola caroliniana (L.) G. Don       00087276U, Hort-004-004
Sida rhombifolia L.    00095695Y, H.S. 212 f.51, H.S. 212 f.50
Digitaria sanguinalis (L.) Scopoli     Sher-0125
Echinochloa crusgalli (L.) Palisot de Beauvois       00087523P
Eleusine indica (L.) Gaertn. H.S. 212 f.85, 00087562S
Eragrostis cilianensis (Allioni) Vignolo ex Janchen           00087570R
Hackelochloa granularis (L.) Kuntze           00087527T

NB: H.S. references are in the Sloane Herbarium. Sher-#### and 00##### references are in the herbaria at Oxford University.


Some introductions were likely deliberate. Nepeta cataria L. (00087449W) is catnip, a common garden herb native to Eurasia. It is easy to imagine a colonist bringing seeds from Europe to start an herb garden in Carolina.   

Tarenaya hassleriana (Chodat) H.H. Iltis (syn. Cleome hassleriana Chodat, 00087297X), is the spiderflower or spider plant commonly grown as an ornamental. The note on the bottom of the herbarium sheet reads “Sent from South Carolina by Mr. Mark Catesby.” This species is native to South America. The Flora of North America describes it thus: “Tarenaya hassleriana is native to Argentina, Brazil, and Paraguay. It is often cultivated and has sometimes escaped and naturalized. In cultivation and various floras, it has long been treated under the name Cleome spinosa…..”.  

Cleome was apparently a favorite of Thomas Jefferson, who grew it in his gardens at Monticello; construction on the house began in 1768 and work on house and gardens continued for several decades. The plant is an aggressive self-seeder.
 
So did Catesby really find this plant in South Carolina? It is plausible; certainly there had been traffic between the cleome’s native range and the Carolinas for decades by the time he visited.
 
The presence of particular taxa in Catesby’s collections may or may not be significant. It is impossible to know where he collected his specimens, or the conditions in which they were growing. He certainly could have gathered plants from cultivated gardens. But it is also possible that some of the introduced plants he collected had already escaped from cultivation. It is also true that we do not know for certain that the plants in the herbaria were collected in Carolina; even the ones with handwritten notes claiming South Carolina provenance might have in fact been collected elsewhere. What we can say, however, is that the presence of these taxa in Catesby’s collections strongly suggests that these plants were growing in South Carolina or possibly Georgia in the 1720s.

Sunday, March 10, 2013

Botanica Caroliniana on the Radio

Amy Hackney Blackwell and Patrick McMillan appeared on the SCETV radio program, Walter Edgar’s Journal. They discuss botany, history, and the importance of curation, both real and digital. You can listen to the interview on the show’s website.

Monday, March 4, 2013

Indigo, before indigo was big


H.S. 232 f.106 contains a specimen of Indigofera tinctoria L., indigo. Solander identified it as such in a hand-written label. Indigo is the source of a blue dye that was in high demand in Europe during the colonial period. (It is still used worldwide today, well known as the dye that makes denim blue.) In principle, it should not be surprising to find indigo among specimens Catesby collected in Carolina. This plant was cultivated as an export crop on the Coastal Plain of Georgia and South Carolina in the 17th and 18th centuries. But Catesby’s specimen predates the widespread commercialization of this plant; South Carolina’s indigo industry did not emerge until about 1740. Is there a story?

Well, maybe. Blue dye was a bigger deal than moderns might appreciate. Indigo was the stuff of fortunes, but only for a while. Economies rose and fell on the human desire for blue cloth.

Before 1500, European cloth manufacturers wishing to dye fabric blue used woad, Isatis tinctoria. Woad is a plant in the mustard family Brassicaceae. It produces the same pigment as indigo but in lower concentrations. It was also the pigment that ancient Britons used to color their bodies blue, the better to dismay the Romans.

Indigo is a better dye than woad. It became available in Europe after trade opened up with the East Indies, and by the late 1600s indigo had become the blue dye of choice for European textile manufacturers. (There was a time when indigo was controversial, and regions passed laws to protect their woad-growers from competition. How times do change.) French, English, and Spanish colonists began growing indigo in the Americas in the first half of the 17th century. Indigo grew well in the Caribbean and Central America.

The Lords Proprietors of Carolina began experimenting with indigo cultivation in the 1670s. The climate of coastal South Carolina proved ideal for growing the crop, and the plants in these initial experimental gardens grew well. By the 1690s, however, the South Carolina indigo experiment had been largely abandoned as economically unviable; West Indian indigo was of higher quality, and rice was a more profitable crop in the Carolinas. In the 1740s Carolina growers once again attempted to grow indigo – Eliza Lucas Pinckney is often credited with establishing the South Carolina indigo industry – and this time the crop was immensely profitable and a good supplement to rice culture. This was true despite the fact that Carolina indigo had a reputation for being of poor quality. By the mid 1700s, European nations were importing two million pounds of indigo annually from the Western Hemisphere. 

Indigo’s profitability to South Carolina lasted only a few decades. By 1800, cotton had replaced it as the cash crop of choice. Indigo perked along as a dye crop for another century, but these days most blue dye is synthetic.

Catesby’s indigo specimen predates the establishment of the Carolina indigo industry by nearly twenty years. This plant may have been a remnant of earlier experiments by the first group of settlers, perhaps using seeds imported from Barbados or Jamaica. It is likely not related to Eliza Pinckney’s later crops, which she grew from seeds her father sent her from the West Indies. 

If you want to read more about the history or economic implications of the SC indigo industry, try:
Coon, David L. 1976. “Eliza Lucas Pinckney and the Reintroduction of Indigo Culture in South Carolina.” The Journal of Southern History 42 (1) (February 1): 61–76. doi:10.2307/2205661.
Nash, R. C. 2010. “South Carolina Indigo, European Textiles, and the British Atlantic Economy in the Eighteenth Century.” The Economic History Review 63 (2): 362–392. doi:10.1111/j.1468-0289.2009.00487.x.



Tuesday, September 18, 2012

Taxonomy - what are we missing?

Theophrastus looked at plants and asked what distinguished one from the other. He saw differences in trees, shrubs, herbs, in roots and leaves, from one plant to the next, and so created the basics of modern taxonomy. Dioscorides looked at plants and asked what they could do for humans. He saw differences in uses, in medical applications and foods, and codified an early version of economic botany.

As fortune would have it, Dioscorides' work thrived from ancient times until the Renaissance. Theophrastus got buried in a pit and mostly forgotten. Plant taxonomy as we know it languished until Europeans regained an interest in the natural world. One big problem? No one knew what to call plants. No one knew if they were talking about the same plant. Local names were handy locally, but worse than useless scientifically. It took Linnaeus and his system of binomial nomenclature to finally make it possible to have a coherent discussion about a particular plant and for all participants to be certain that they were discussing the same thing. (See Anna Pavord's book The Naming of Names for an excellent overview.)

Linnaeus and his descendant taxonomists follow essentially the same rules as Theophrastus. They look at physical features of plants. Plants that share features get grouped together. Genetics and DNA mapping have allowed taxonomists to create groupings that are more evolutionarily accurate than groupings created by mere gross physical resemblance - for example, Sarracenia and Nepenthes are not close relatives even though they are both types of insectivorous pitcher plants - but the principle remains the same, plants grouped on the basis of physical similarity.

All of this means that plant taxonomy is a weird, free-floating subject of study. We memorize identifying features such as placentation, leaf arrangement, number of carpels and ovary placement. We use these traits in dichotomous keys to place plant specimens into families, genera, or species. So, for example, we know that members of the family Salicaceae are trees or shrubs, the lowermost bud scale is centered over the leaf scar, the flowers are reduced, unisexual, and subtended by hairy bracts, and that the fruits are loculicidal capsules. Members of the Fabaceae have root-nodules containing nitrogen-fixing bacteria, alternate leaves that are typically compound, stipules that range from inconspicuous to leaf-like, and usually five sepals.

But what does that tell me? These synapomorphies, or shared features, are the result of evolution, of millions of years of natural selection. The social Hymenoptera, which include bees and ants, appeared during the Cretaceous (145-65 mya). Angiosperms appeared between 130 and 125 million years ago. The Asteraceae appeared around 50 million years ago, during the Cenozoic era. The Cenozoic started 65 million years ago, after the end of the Cretaceous, and after the dinosaurs disappeared. This was the age of mammals, but also of various other kinds of life, especially insects. The Asteraceae thrived and radiated during the unstable climate of the Pleistocene - 2.5 million to 12,000 years ago - downright recent by human standards.

Homo sapiens, on the other hand, appeared about 200,000 years ago, and only got to looking and acting modern 50,000 years ago. What have we to do with plants? They were all here when we arrived on the scene - whatever morphological features they "chose" were not chosen with us in mind. Plants are speaking a very different language from ours, and on a different timescale. They were formed by insects and other animals and climates and geography that we can never know.

This, I think, is why economic botany tends to win out over pure systematics. We teach students economically important plants in each major plant family - peaches come from Rosaceae, cotton from Malvaceae - because otherwise it is awfully difficult to persuade them that they should know the classifications. The plants simply aren't talking to us. We don't assess flowers for landing strips or accessibility for our probosces. A magnolia flower has a lot to say to a beetle and rose perfume says a lot to bees, but to us they're just pretty. The ginkgo still makes fruit that may have been custom-blended by dinosaurs, and the durian makes giant spiny fruits that might have been intended for elephants. (Connie Barlow, The Ghosts of Evolution.) No wonder we focus our study on "useful" plants - otherwise we feel left out of the discussion.

Pure taxonomy - we need the names named, so that we can know what we're talking about. But I find it tantalizing, dancing around real answers. How is it that I can study botany for years and still can barely identify a single insect? Why are we studying plants in splendid isolation, instead of pairing them with their many partners? Why doesn't taxonomy start with a chronology, slotting plants in where they appeared, along with animals and other living organisms and continental positions and climate? (That's a poster I've been planning to make for years. Complicated, it is.)

There is so much more to why plants are what they are than their medical and fiber applications. Applied plant science is all very well, but the full story is so much more interesting. Even if it's still fragmentary, we could be telling it.