pteridologist

Lellingeria was named for the American pteridologist David Lellinger.

But Sacks the pteridologist?

A pteridologist is a specialist in the study of pteridophytes in a broader sense that includes the more distantly related lycophytes.

The specific epithet croftii commemorates pteridologist James R. Croft (b. 1951).

The specific epithet elmeri commemorates pteridologist Adolph Daniel Edward Elmer (1870-1942).

The specific epithet christii commemorates Swiss pteridologist Konrad Hermann Heinrich Christ (1833-1933).

The specific epithet metteniana commemorates pteridologist Georg Heinrich Mettenius (1823-1866), who himself named several Cyathea species.

The study of ferns and other pteridophytes is called pteridology, and one who studies ferns and other pteridophytes is called a pteridologist.

Mickelia was named for the American pteridologist John Thomas Mickel, who contributed much regarding Elaphoglossum, the closest relative of Mickelia.

C. alderwereltii is named after Cornelis Rogier Willem Carel van Alderwerelt van Rosenburgh (1863-1936), a Dutch pteridologist who worked extensively in the Sunda region.

The East-Asian genus Christensenia is named in honor of the Danish pteridologist Carl Christensen is an uncommon fern with distinctive fronds resembling a horse chestnut leaf, hence the species Christensenia aesculifolia, meaning horse-chestnut-leaved Christensenia.

As curator of cryptogamic botany, Rogerson "was directly responsible for all accessions and loans of ferns and mosses, as well as of fungi and lichens, until about 1965 when, first a bryologist and later a pteridologist were added to the cryptogamic staff."

Reinhard Gustav Paul Knuth (1874-1957) was a German taxonomist, botanist and pteridologist responsible for "Initia florae venezuelensis" in 1928, and numerous contributions to Adolf Engler's "Das Pflanzenreich" on Geraniaceae, Oxalidaceae, Lecythidaceae, and other families.