1803 Tho Jefferson (1743-1826) 1803 orders Lewis & Clark & Botanist F T Pursh to collect America's Plants

William Clark (1770-1638) & Meriwether Lewis (1774-1809)

"Washington D.C., June 20, 1803
Thomas Jefferson To Meriwether Lewis Esquire, Capt of the first regiment of Infantry of the United States of America.
The Object of your mission is to explore the Missouri river & such principal stream of it as by it's course & communication with the waters of the Pacific ocean, whether the Columbia, Oregon, Colorado or any other river may offer the most direct & practicable water communication across this continent for the purpose of commerce."

The Lewis & Clark Expedition from May 1804 to Sept 1806, also known as the Corps of Discovery Expedition, was the first American expedition to cross what is now the western portion of the United States. It began near St. Louis, made its way westward, & passed through the continental divide to reach the Pacific coast. The Corps of Discovery comprised a selected group of U.S. Army volunteers under the command of Capt Meriwether Lewis (1774-1809) & his close friend, Second Lieutenant William Clark (1770-1638).

Thomas Jefferson hoped the Lewis & Clark Expedition would provide a window onto the West. The men of the Expedition were to observe & record everything, from the languages of the Indians to the dates when plants flower. In fulfilling Jefferson’s charge, the explorers became capable amateur scientists. In preparation for the journey, Lewis studied with the best scientists in Philadelphia. As the Corps traveled, the men of the Expedition pressed plants & wrapped them all in oilcloth to protect them from rain & river water. They wrote detailed descriptions & sometimes drew what they saw around them. In 1806, back in Washington, Lewis laid out the map Clark had drawn & he & Jefferson looked onto the West. It would be many years before the rest of the world had the same opportunity. The official Expedition journals & Clark’s map were not published until 1814, 8 years after the journey.

President Jefferson instructed Meriwether Lewis to collect information on “the soil & face of the country, [its] growth & vegetable productions… the animals of the country generally, especially those not of the U.S.” In fulfilling these instructions, members of the Expedition were the first to describe for science 178 plants. Lewis lost the notes about the specimens but analyses & detailed scientific descriptions of the specimens were performed by others.  Lewis described & published none of the plants he collected in the Western America.  

Lewis hired Frederick Traugott Pursh (1774-1820) in Rhode Island to review the plant collection & describe & publish the results. Pursh was a German–American botanist. Born in Saxony, he was educated at Dresden Botanical Gardens, & emigrated to the United States in 1799. From 1802 to 1805, he worked in Philadelphia as the botanical manager of the extensive gardens of William Hamilton, Esq., at "The Woodlands." In the dozen years he spent in the United States he was employed by some of the country's leading botanists, including William Bartram, Bernard McMahon & Benjamin Smith Barton.  By 1805, he was working for Benjamin Smith Barton on a new flora of North America, under whom he studied the plants collected on the Lewis & Clark Expedition.  In 1805, Pursh traveled south from Maryland to the Carolinas and, in 1806, he traveled north from the mountains of Pennsylvania to New Hampshire. Pursh made both trips principally on foot, with only his dog & a gun, covering over 3,000 miles each season. In 1807, Pursh became one of the first directors of the New York Botanical Garden.  Barton's proposed flora was never written, but Pursh, who then moved to London, England, did make a major contribution to North American botany in his 1814 Flora americae septentrionalis; or A Systematic Arrangement & Description of The Plants of North America.  

Plants Collected on Lewis & Clark Expedition

May 21–July 31, 1804

Common name Species
Lemon Scurfpea                 Psoralidium lanceolatum
Osage Orange Tree             Maclura pomifera

Aug 1804

Curlycup Gumweed     Grindelia squarrosa
Lg-Flowered                          Clammyweed Polanisia trachysperma
Prairie Apple                        Psoralea esculentum
Rocky Mountain Bee Plant     Cleome serrulata

Sept 1804

Aromatic Aster                 Symphyotrichum oblongifolium
Broom Snakeweed         Gutierrezia sarothrae
Four-Wing Saltbush             Atriplex canescens
Lacy Tansyaster             Machaeranthera pinnatifida
Missouri Milkvetch             Astragalus missouriensis
Silvery Buffaloberry             Shepherdia argentea
Slimflower Scurfpea             Psoralidium tenuiflora
Tarragon                            Artemisia dracunculus

Oct 1–Dec 20, 1804

Gray Rabbitbrush                Ericameria nauseosa
Indian Breadroot                Pediomelum argophyllum
Indian Tobacco                 Nicotiana quadrivalvis
Long-Leaved Mugwort         Artemisia longifolia
Prairie Rose                        Rosa arkansana
Squaw Bush                        Rhus trilobata

Dec 21, 1804–Apr 6, & Apr 7–May 3, 1805

Purple Coneflower         Echinacea angustifolia

May 4–28, & May 29–June 11, 1805

Fragile Prickly-Pear         Opuntia fragilis
Tansy                             Sphaeromeria argentea

June 12–July 20, 1805

Mountain Lady's Slipper         Cypripedium montanum
Narrowleaf Cottonwood         Populus angustifolia
White Squaw Currant         Ribes cereum

July 21–Aug 7, 1805

Dwarf Thistle            Cirsium drummondii
Water Birch                Betula occidentalis

Aug 8–24, 1805

Lewis Monkeyflower         Mimulus lewisii
Rocky Mountain Maple         Acer glabrum
Western Red Baneberry         Actaea rubra ssp. rubra

Aug 25–Oct 7, 1805

Common snowberry             Symphoricarpos albus
Dwarf Mountain Fleabane     Erigeron compositus
Engelmann's Spruce             Picea engelmannii
Lodgepole Pine                     Picea contorta
Pacific Yew                         Taxus brevifolia
Ponderosa Pine                 Pinus ponderosa
Sitka Alder                         Alnus viridis ssp. sinuata
Sitka Mountain Ash             Sorbus scopulina
Subalpine fir                     Abies lasiocarpa
Western Larch                     Larix occidentalis
Western Red Cedar             Thuja plicata
Whitebark Pine                 Pinus albicaulis

Oct 8–Dec 7, 1805

California hazelnut                 Corylus californica
California Rhododendron         Rhododendron macrophyllum
Dwarf Mountain Fleabane         Erigeron compositus
Eaton's Aster                         Symphyotrichum eatonii
Mountain Balm                     Ceanothus velutinus
Netleaf Hackberry                 Celtis reticulata
Oregon Ash                         Fraxinus latifolia
Oregon Boxleaf                     Paxistima myrsinites
Pacific Madrone                     Arbutus menziesii
Peach-Leaved Willow             Salix amygdaloides
Prickly-Pear Cactus                 Opuntia polyacantha
Slender Willow                     Salix exigua
Vine Maple                         Acer circinatum
White Alder                         Alnus rhombifolia

Dec 8–30, 1805 & Dec 31, 1805–Mar 22, 1806

Blue Elderberry                 Sambucus glauca
Blue Huckleberry                 Vaccinium membranaceum
Edible Thistle                     Cirsium edule
Evergreen Huckleberry         Vaccinium ovatum
Grand Fir                             Abies grandis
Lyall's Nettle                         Urtica lyallii
Mountain Hemlock                 Tsuga mertensiana
Oregon Crab Apple                 Pyrus fusca
Oregon Wood Sorrel             Oxalis oregana
Pacific Blackberry                 Rubus vitifolius
Salal                                     Gaultheria shallon
Seashore Lupine                     Lupinus littoralis
Sitka Spruce                         Picea sitchensis
Western Bracken                 Pteridium aquilinum ssp. pubescens
Western White Pine             Pinus monticola

Mar 23–Apr 28, 1806

Big Sagebrush                     Artemisia tridentata
Bigleaf Maple                     Acer macrophyllum
Canyon Gooseberry             Ribes menziesii
Cascade Oregon-Grape         Mahonia nervosa
Chocolate Lily                     Fritillaria affinis
False Buckthorn                 Rhamnus purshiana
Golden Currant                     Ribes aureum
Hollyleaf Oregon-Grape     Mahonia aquifolium
Large-Flower Tritelia         Triteleia grandiflora
Large-Head Clover            Trifolium macrocephalum
Lindley's Silverpuffs         Uropappus lindleyi
Linear-Leaved Phacelia     Phacelia linearis
Maiden Blue-Eyed Mary      Collinsia parviflora var. grandiflora
Menzies' Larkspur              Delphinium menziesii
Narrowleaf Mountain-Trumpet     Collomia linearis
Nuttall's toothwort                 Cardamine nuttallii
Oregon White Oak                 Quercus garryana
Pacific Dogwood                 Cornus nuttallii
Pestle Parsnip                     Lomatium nudicaule
Red Alder                             Alnus rubra
Red-Flowering Currant         Ribes sanguineum
Salmonberry                             Rubus spectabilis
Slender Popcorn Flower             Plagiobothrys tenellus
Straggly Gooseberry             Ribes divaricatum
Thimbleberry                 Rubus parviflorus
Western Serviceberry             Amelanchier alnifolia
Western Sweetroot             Osmorhiza occidentalis
Western Wake-Robin             Trillium ovatum
Wormwood                             artemisia ludoviciana

Apr 29–June 9, 1806

Black Hawthorn                     Crataegus douglasii
Cat's Ears                                 Calochortus elegans
Cous                                         Lomatium cous
Deerhorn Clarkia                         Clarkia pulchella
Desertparsley                             Lomatium triternatum
Disc Mayweed                         Matricaria discoidea
Geyer's Onion                  Allium geyeri
Giant Rye Grass                 leymus condensatus
Golden Yarrow                     Eriophyllum lanatum
Green Rabbitbrush                 Chrysothamnus viscidiflorus
Lewis's Mock Orange         Philadelphus lewisii
Mountain Brome                 Bromus marginatus
Narrow-Leaved Skullcap     Scutellaria angustifolia
Ocean Spray                         Holodiscus discolor
Orange Honeysuckle         Lonicera ciliosa
Showy Phlox                     Phlox speciosa
Silky Lupine                     Lupinus sericeus
Spring Birch                     Betula occidentalis
Sugarbowls                     Clematis hirsutissima
Tolmie's Onion             Allium tolmiei
Varileaf Phacelia         Phacelia heterophylla
Western Wallflower         Erysimum capitatum
Wilcox's Beardtongue         Penstemon wilcoxii
Yellow Bell                     Fritillaria pudica