| American botanist |
| Pioneering botanist |
| Darwin's American ally |
| Noted 19th-century botanist |
| 19th-century American botanist |
| Renowned 19th century botanist |
| Harvard University Herbaria founder |
| A Free Examination of Darwin's Treatise" scientist |
| To whom Charles Darwin dedicated "Different Forms of Flowers |
| Name on the highest award of the American Society of Plant Taxonomists |
| Botanist who arranged "On the Origin of Species" to be published in the States |