Synopsis methodica stirpium Britannicarum : in qua tum notae generum characteristicae traduntur, tum species singulae breviter describuntur: ducentae quinquaginta plus minus novae species partim suis locis inseruntur, partim in appendice seorsim exhibentur : cum indice & virium epitome - Ray, John, 1627 -1705 (Prostant apud Sam. Smith ad insignia principis in coemeterio D. Pauli, 1690)

Synopsis of British seaweeds - Harvey, William H. (William Henry), 1811 -1866 (L. Reeve, 1857)

A synopsis of North American lichens Part II, comprising the lecideacei, and (in part) the graphidacei - Tuckerman, Edward, 1817 -1886 (s.n.], 1888)

A synopsis of the genus Arthonia - Willey, Henry, 1824 -1907 (Willey, 1890)

A synopsis of the lichenes of New England, the other northern states, and British America - Tuckerman, Edward, 1817 -1886 (G. Nichols, 1848)

A synopsis of the North American lichens - Tuckerman, Edward, 1817 -1886 (S. E. Cassino, 1882)

A synopsis of the North American lichens Part I, comprising the parmeliacei, cladoniei, and coenogoniei - Tuckerman, Edward, 1817 -1886 (S.E. Cassino, 1882)

Synopsis of the North American lichens, Pt. 1: comprising the Parmeliacei, Cladoniei, and Coenogomei - Tuckerman, Edward, 1817 -1886 (1882)

Synopsis plantarum in flora Gallica descriptarum - Candolle, Augustin Pyramus de, 1778 -1841 (Apud H. Agasse, 1806)

Synoptical flora of North America - Gray, Asa, 1810 -1888 (American Book Company, 1895)

Synoptical flora of North America - Gray, Asa, 1810 -1888 (American Book Company, 1884)

Das system der pilze und schwämme. Ein versuch - Nees von Esenbeck, C. G. (Christian Gottfried), 1776 -1858 (In der Stahelschen buchhandlung, 1816)

A system of physiological botany - Keith, Patrick, 1769 -1840 (Printed for Baldwin, Cradock, and Joy, 1816)

Systema algarum - Agardh, C. A. (Carl Adolf), 1785 -1859 (Literis Berlingianis, 1824)

Systema characterum plantarum; seu, Dictionarium rerum botanicum, filio conscriptum, et ab ipso figuris illustratum - Pereboom, Cornelius. (1788)

Systema mycologicum : sistens fungorum ordines, genera et species, huc usque cognitas, quas ad normam methodi naturalis determinavit - Fries, Elias, 1794 -1878 (Ex Officina Berlingiana, 1821)

Systema naturae per regna tria naturae : secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae, 1767)

Systema naturae, per regna tria naturae : secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae, 1767)

Systema naturae, per regna tria naturae : secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis - Linné, Carl von, 1707 -1778 (Typis Ioannis Thomae, 1770)

Systema plantarum Europae, exhibens characteres naturales generum, characteres essentiales generum & specierum, synonima antiquorum, phrases specificas recentiorum Halleri, Scopoli, &c. Descriptiones rariorum, nec-non floras tres novas, Lugdunaeam, Delphinalem, Lithuanicam, non omissis plantis exoticis in hortis Europae vulgo obviis - Linné, Carl von, 1707 -1778 (Sumptibus Piestre & Delamolliere, 1785)