Ben Nicholson; Tree at Saval; 1958; pencil and wash; 51 x 36 cm

John Constable; Sky Study with Tree; watercolor; British Museum

Philip Wilson Steer; Elm Tree; 1922; watercolor

Boris Anisfeld; Tulips; 19th-20th century; 30.9 x 22.6 cm; Fine Arts Museums of San Francisco

Anonymous (Asian, Indian); Study of the floral pieta dura in the Tomb of Arjumand Banu in the Taj Mahal at Agra; c.1835; transparent and opaque watercolor on paper; 29.1 x 22.1 cm; Fine Arts Museum of San Francisco

Thomas Daniell; Nearly Opposite Hoogley, N. 40 from an unidentified sketchbook; c.1784-94; watercolor over graphite on laid paper; Fine Arts Museum of San Francisco

attrib. to Salvator Rosa; Landscape; 17th-18th century; red chalk on laid paper; 26.1 x 19.2 cm; Fine Arts Museums of San Francisco

Chiang Su; Quince Blossoms; 18th century; opaque watercolor on silk mounted to paper support; 30 x 21.2 cm; Fine Arts Museum of San Francisco

Anonymous (Asian, Indian); Study of the flora pietra dura in the Tomb of Arjumand Banu in the Taj Mahal at Agra;c.1835; transparent and opaque watercolor on paper; 28.9 x 21.9 cm; Fine Arts Museums of San Francisco

Bartolomeo Pinelli; Figures Listening to a Tale, Ensconced in a Classical Landscape; 1824; pen and black ink over graphite on laid paper; 23 x 33.1 cm; Fine Arts Museums of San Francisco

Giovanni Francesco Grimaldi; Landscape;17th century; pen and brown ink over black chalk; 14 x 25.2 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (36) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; stenciled transparent and opaque watercolor with pastel on paper; 22.1 x 15.8 cm; Fine Arts Musuem of San Francisco

Charles Carrick; Page (42) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; stenciled watercolor with metallic pigment and pastel on paper; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (73) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (136) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; prints of real leaves, stenciled transparent and opaque watercolor, pastel on paper; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (146) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; prints from real leaves, stenciled transparent and opaque watercolor, pastel and pen and ink on paper; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (186) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; pen and ink on paper; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (24) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; stenciled watercolor, with pen and ink, pastel, and leave prints; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (72) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; prints from leaves, grasses, or fir needles, stenciled and sponged transparent and opaque watercolor, metallic pigments and pastels on paper; 22.1 x 15.8 cm; Fine Arts Museums of San Francisco

Charles Carrick; Page (116) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; prints from leaves, transparent and opaque watercolor, metallic pigments, pen and ink and pastel on paper; 22.1 x 15.8 cm; Fine Arts Museum of San Francisco

Charles Carrick; Page (118) from the book, Flights of Fancy or Imaginary Scraps; c.1842-77; leaf print and pastel on paper; 22.1 x 15.8 cm; Fine Arts Museums of San Francisco

John La Farge; The Great Statue of Amida Buddha at Kamakura; c.1887; watercolor over graphite on wove paper; 40.5 x 49.2 cm; Fine Arts Museum of San Francisco

Hironari; Baby Eggplants; c.1820; brush and sumo ink on a sheet of Japanese album paper with printed border design; 19.5 x 26.4 cm; Fine Arts Museums of San Francisco

Gerrit Schouten; Botanical Study: Araccae (Palmae), Atrocayum vulgare; 1824; watercolor; 59.8 x 45.7 cm; Fine Arts Museums of San Francisco

Vincent van Gogh; Untitled Botanical Study; 1863; Kröller-Müller Museum, Otterlo, Gelderland, Netherlands

Max Ernst; The Gramineous Bicycle; c.1921; gouache and ink on botanical chart; Museum of Modern Art, New York, NY

Leonardo da Vinci; Star of Bethlehem (Ornithogalum umbellatum) and anemones (Anemone bulbosa, Anemone ranunculoides); c.1506-8; pen and ink over red chalk on paper; 198 x 160 mm; Windsor Castle, Windsor, England, UK

Paul Klee; Botanical Laboratory; 1928; gouache, watercolor and ink on paper mounted on cardboard; 39.37 x 26.9875 cm; The Phillips Collection, Washington DC

George Elbert Burr; Untitled (Botanical Study); 1889; pencil on paper; 36.4 x 27.8 cm; Smithsonian American Art Museum

Pancrace Bessa; Botanical Design; watercolor and lead point on vellum; 266 x 207 mm; Cleveland Museum of Art

Pancrace Bessa; Botanical design; watercolor, pencil, lead point on vellum; 262 x 208 mm; Cleveland Museum of Art

Sergei Chekhonin; 1914; mixed media on yellow paper; 33.5 x 24.9 cm

Philipp Otto Runge; Construction of a Cornflower; 1808-9; pen, ink, pencil on paper; 25 x 19.4 cm

Vincenzo Leonardi; Citron and sour orange, Citrus medica L. and Citrus aurantium L.: chimeric half-fruit; watercolor and bodycolor, with gum heightening, over black chalk and incised lines; 129 x 130 mm; Windsor Castle, Royal Library, UK

Citrus, Citrus: ribbed misshapen fruit; watercolor and bodycolor, with gum heightening, over black chalk; 137 x 193 mm; Windsor Castle, Windsor, UK

Citrus, Citrus sp.: fruiting branch; watercolor and body color over graphite; 312 x 205 mm

Giovanni Battista Ferrari; Hesperides: Malum citreum vulgare; etching and engraving; 1646

Giovanni Battista Ferrari; Hesperides: Malum citreum multiforme; etching and engraving; 1646

Giovanni Battista Ferrari; Hesperides: Alia lima citrata oblonga sive scabiosa et mostrosa; etching and engraving; 1646

Vincenzo Leonardi; Lemon, Citrus limon (L.) Burm. f.; fingered whole fruit; watercolor and body color over black chalk, badly rubbed; 80 x 90 mm; Windsor Castle, Windsor, UK

Vincenzo Leonardi; Lemon, Citrus limon (L.) Burm. f.: fingered whole fruit: watercolor and body color over black chalk, badly rubbed; 88 x 115 mm

Frederick Polydor Nodder, after Sydney Parkinson; Family: Euphorbiaceae, Genus/Species: Poranthera microphylla; 1780; Natural History Museum, London

Albrecht Dürer; Willow Mills on the Pegnitz; c.1496-8; watercolor and gouache on paper; 251 x 367 mm; Bibliothèque national de France

Albrecht Dürer; Tuft of Cowslips; 1526; watercolor and body color on vellum, brush, heightened with white; 192 x 168 mm; The Armand Hammer Museum of Art and Cultural Center, Los Angeles, CA

Albrecht Dürer; Columbine; 1526; watercolor and bodycolor, brush, heightened with white, on vellum, mounted on cardboard; 356 x 287 mm; Albertina, Vienna, Austria

Albrecht Dürer; Iris; 1508; watercolor, brush, pen; 775 x 313 mm; Kunsthalle Bremen

Albrecht Dürer; Landscape Flooded with Waters from Heaven; 1525; pen and watercolor; 30 x 42 cm

Albrecht Dürer; Quarry; 1495-7; watercolor; 225 x 287

Albrecht Dürer; Quarry; 1495-7; watercolor; 292 x 224 cm

Albrecht Dürer; Three Lime Trees; c.1489; watercolor; 34.3 x 27.9 cm

Georgia O’Keeffe; Banyan Tree; 1937; graphite on paper; Georgia O’Keeffe Museum

Anonymous Italian artist; Study of a tree in leaf; late 16th century; 425 x 276mm; Victoria and Albert Museum, London, UK

Pierre Daura; untitled (tree limbs and roots); 1934; ink on paper; 25.4 x194 cm; Terra Foundation for American Art

George Elbert Burr; Roche Vaud; 1899; pencil on paper; 12.4 x 19.6 cm; Smithsonian American Art Museum Collection

Claude Lorrain; Oak in Vigna Madama; 1638; pen and brown ink and brown wash over graphite; 330 x 224 mm; British Museum

Peeter Boel; A Broken Tree Overhanging a Stream; 1637-74; black chalk, with some graphite; 350 x 248 mm; British Museum

Peter von Bemmel; Study of a tree; chalk; 305 x 205 mm; British Museum

Claude Lorrain; Landscape with Herdsman and Shepherds Under Tree; British Museum

Paul Nash; Landscape with Tree and Girl; drawing; Victoria and Albert Museum, London, UK

Claude Lorrain; Hilly Landscape Seen Between Tree Trunks; 1638-40; brush drawing in brown wash, over graphite; 221 x 330 mm; British Museum

Helen Paterson Allingham; The Lower Trunk of a Yew Tree, at Northfield; brush drawing in grey ink; 190 x 137 mm; British Museum

Abraham Bloemaert; Trunk of Tree with Two Figures; pen and wash; 260 x 166 mm; Victoria and Albert Museum

Frederic William Burton; A Mossy Tree Trunk; watercolor; 210 x 269 mm; British Musuem

Claude Lorrain; A Tree; 1635; pen and brown ink, brown and grey wash; 175 x 225 mm; British Museum

Samuel Palmer; Larger Study of a Tree; c.1824; brush drawing in black ink, touched with watercolor on paper; 189 x 116 mm; British Museum

Claude Lorrain; Pine Tree; 1665; pen and brown ink over graphite; 388 x 260 mm; British Museum

Anthonie Waterloo; Study of a Leaning Tree; mid 17th century; black chalk, with gray wash, on cream paper;204 x 312 mm; British Museum

Govaert Flinck; Landscape with a Large Tree; 1642; pen and ink, watercolor on paper; 190 x 195 mm; British Museum

Albrecht Dürer; Pine Tree; 1495-9; watercolor; 295 x 196 mm

Arthur Garfield Dove; Walk: Poplars or Poplar Tree; c.1912-3; pastel on linen; Terra Museum of American Art

Vincent van Gogh; Tree with Ivy in the Garden of the Asylum at Saint-Rémy; 1889; reed pen, brush, and ink, graphite on laid paper; 61.8 x 47.1 cm; Van Gogh Museum, Amsterdam, North Holland, Netherlands

Vincent van Gogh; Study of a Tree; 1882; crayon, pencil, watercolor, lightly washed; 48.9 x 68.6 cm; Kröller-Müller Museum, Otterlo, Gelderland, Netherlands

Paul Sanby; Study of a Tree: Windsor Castle in the Distance; c.1780s; watercolor, pen and ink over pencil on paper; Ashmolean Museum

Salvatore Rosa; Landscape with Man and Tree; c.1649; feather and ink on wood; 28 x 50 cm; Palazzo Pitti