"Nepenthaceae" is a monograph by John Muirhead Macfarlane on the tropical pitcher plants of the genus Nepenthes. It was published in 1908 in Adolf Engler's Das Pflanzenreich. It was the most exhaustive revision of the genus up to that point, covering all known species, and included detailed accounts of the structure, anatomy, and development of Nepenthes. Content Macfarlane recognised 58 species, including 8 newly described ones: N. anamensis (later synonymised with N. smilesii), N. beccariana, N. copelandii, N. deaniana, N. hemsleyana, N. neglecta (possibly the natural hybrid between N. gracilis and N. mirabilis), N. philippinensis, and N. tubulosa (later synonymised with N. mirabilis). Macfarlane also described a number of new varieties, including N. alata var. biflora (later synonymised with N. negros), N. alata var. ecristata (later synonymised with N. kurata), N. albomarginata var. rubra, N. hirsuta var. glabrata, N. hirsuta var. typica, N. tentaculata var. tomentosa, and N. vieillardii var. montrouzieri. The varietal name N. gracilis var. arenaria, originating from a herbarium sheet, also appeared in print for the first time in Macfarlane's monograph. The work included all manmade hybrids known at the time. Macfarlane synonymised a number of species, including N. korthalsiana with N. gracilis, N. macrostachya with N. mirabilis, N. sumatrana with N. treubiana (later reversed), and both N. teysmanniana and N. tomentella with N. albomarginata. Macfarlane restored N. edwardsiana as a species distinct from N. villosa. This decision was reversed by B. H. Danser in his 1928 work, "The Nepenthaceae of the Netherlands Indies", but is universally accepted today. Macfarlane recognised N. × cincta as a natural hybrid between N. albomarginata and N. northiana, and N. × harryana as a natural hybrid between N. edwardsiana and N. villosa. Species The following 58 taxa are enumerated and detailed in Macfarlane's "Nepenthaceae". Varieties recognised by Macfarlane are also included. Taxon names are listed as they appear in the monograph, including orthographic variants, though specific epithets derived from proper nouns have been decapitalised. N. alata var. biflora var. ecristata N. albo-lineata N. albo-marginata var. rubra var. villosa N. alicae N. ampullaria var. geelvinkiana var. longicarpa N. anamensis N. angustifolia N. armbrustae N. beccariana N. bernaysii N. bicalcarata N. blancoi N. bongso N. boschiana N. burbidgei N. burkei var. excellens var. prolifica N. cholmondeleyi N. copelandii N. deaniana N. distillatoria N. echinostoma N. edwardsiana N. eustachya N. garrawayae N. gracilis N. hemsleyana N. hirsuta var. glabrata var. typica N. hookeriana N.