Complex Nepenthes hybrids with valid names
Published online (2022).

On the main page, I talked about some stats I did, based on the CPD alone:
there are 186 hybrids, which have been given 455 different names. Of these 455 names, 234 are latin names and 221 are cultivar names. There are 37 latin names that can boast to be the first validly published for the hybrid. Of these 37 names, 22 belong to simple hybrids (two parents) and 15 belong to complex hybrids (more than two parents). I thought those 15 were worth some extra attention, so here they are.

Related articles:
N. x hybrida and N. x sedenii: by Bruce Bednar, about the two problematic and often used hybrids and about the Victorian confusion between N. mirabilis, N. gracilis, N. hirsuta, N. khasiana and N. distillatoria.
An abridged history of Nepenthes: by Harry James Veitch, is there any better source for information about hybrids than the person who produced them?

N. x atrosanguinea

N. x balfouriana

N. x boisiana

N. x chelsonii

N. x courtii
N. x deslogesii

N. x dormaniana

N. x formosa

N. x hoelscheri

N. x lyrata
N. x outramiana

N. x picturata

N. x rubromaculata

N. x rufescens

N. x stewartii

distillatoria x gracilis x khasiana
N. x atrosanguinea

Bred and grown by James Taplin, South Amboy, New Jersey, US, as of 1882.
Holotype: from material cultivated at Parker & Williams nursery, Upper Holloway, UK (possibly held at herbarium K).
Name published by Maxwell T. Masters on The Gardeners' Chronicle ser. 2, vol. 17: 826 (1882) (description).
Parents:
Description: probably N. xsedenii x rubra.
CPD: N. distillatoria x (gracilis x khasiana).
Macfarlane (1908): probably N. xsedenii x distillatoria.

khasiana x maxima x northiana x sanguinea
N. x balfouriana

Bred and grown by George Tivey, Chelsea (Veitch Nurseries), UK, as of 1899.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Maxwell T. Masters) on The Gardeners' Chronicle ser. 3, vol. 26: 90 (1899) (description).
Parents:
Description: N. xmixta (N. curtisii x northiana) x xmastersiana (N. khasiana x sanguinea).
CPD: N. (northiana x maxima) x (sanguinea x khasiana).
Macfarlane (1908): N. xmixta (N. maxima x northiana) x xmastersiana (N. khasiana x sanguinea).
Herbarium MO specimens: link (1928), link (1942).

ampullaria x maxima x mirabilis x rafflesiana x veitchii
N. x boisiana

Bred and grown by René Jarry-Desloges, Remilly, France, as of 1905.
Holotype: from material cultivated at Remilly (possibly held at herbarium K).
Published by René Jarry-Desloges on The Gardeners' Chronicle ser. 3, vol. 38: 379 (1905) (description).
Parents:
Description: N. xtiveyi (N. curtisii x lanata) x xmorganiae.
CPD: N. (maxima x veitchii) x (mirabilis x (rafflesiana x ampullaria)).
Macfarlane (1908): N. xtiveyi (N. maxima var. superba x veitchii) x morganiana? (N. xhookeriana? x phyllamphora).

ampullaria x hirsuta x rafflesiana
N. x chelsonii

Bred and grown by John Seden, Chelsea (Veitch Nurseries), UK, as of 1871.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Maxwell T. Masters) on The Gardeners' Chronicle 1872: 542 (1872) (description).
Parents:
Description: N. rafflesiana (= N. hookeri) x xdominii.
CPD: N. (rafflesiana x hirsuta) x (rafflesiana x ampullaria).
Macfarlane (1908): N. xhookeriana x xdominii (N. rafflesiana x sp. ?).
Herbaria MO and NHN-L specimens: link (year?), link (year?), link (1892), link (1917), link (1918), link (1928), link (1928), link (1942), link (1942), link (1942).

gracilis x hirsuta x rafflesiana
N. x courtii

Bred and grown by William Court, Chelsea (Veitch Nurseries), UK, as of 1877.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Wilson) on The Gardeners' Chronicle ser. 2, vol. 8: 441 (1877) (description).
Parents:
Description: N. sp. Borneo x xdominii.
CPD: N. gracilis x (rafflesiana x hirsuta).
Macfarlane (1908): N. sp. Borneo x xdominii (N. rafflesiana x sp. Borneo).
Herbarium MO specimen: link (1917).

maxima x northiana x veitchii
N. x deslogesii

Bred and grown by René Jarry-Desloges, Remilly, France, as of 1905.
Holotype: from material cultivated at Remilly (possibly held at herbarium K).
Published by René Jarry-Desloges on Le Jardin 19: 136 (1905) (description).
Parents:
Description: N. xtiveyi (N. curtisii x lanata) x xmixta.
CPD: N. (maxima x veitchii) x (northiana x maxima).
Macfarlane (1908): N. xtiveyi (N. maxima var. superba x veitchii) x xmixta (N. maxima x northiana).

gracilis x khasiana x mirabilis
N. x dormaniana

Bred and grown by James Taplin, South Amboy, New Jersey, US, as of 1882.
Holotype: from material cultivated at South Amboy (possibly held at herbarium K).
Name published by Maxwell T. Masters on The Gardeners' Chronicle ser. 2, vol. 17: 525 (1882) (description).
Parents:
Description: parents unknown.
CPD: N. mirabilis x (gracilis x khasiana).
Macfarlane (1908): probably N. rafflesiana x xsedenii.
The name appeared as N. dormaniana in 1880. That should be from Charles Dorman, a British orchid expert who also named Cattleya dormaniana after his son Arthur Dorman. Later on, the name appeared as N. dormanniana, and I can't find a reason for that.
Herbaria P and NHN-L specimens: link (year?), link (year?).

ampullaria x distillatoria x hirsuta x rafflesiana
N. x formosa

Bred and grown by Harry James Veitch, Chelsea (Veitch Nurseries), UK, as of 1895.
Holotype: from material cultivated at Veitch Nurseries (held at herbarium K).
Published by Veitch Nurseries on Kew Bulletin 1896: 50 (1896) (description).
Parents:
Description: N. xchelsonii x distillatoria.
CPD: N. ((rafflesiana x hirsuta) x (rafflesiana x ampullaria)) x distillatoria.
Macfarlane (1908): N. xchelsonii x distillatoria.
Herbarium NHN-L specimen: link (year?).

distillatoria x gracilis x hirsuta x maxima x northiana x rafflesiana
N. x hoelscheri

Bred and grown by Carl Bonstedt, Goettingen, Germany, as of 1931.
Holotype: from material cultivated at Goettingen Botanical Garden (possibly held at herbarium GOET).
Published by Carl Bonstedt on Pareys Blumengärtnerei 1, ed. 1: 666 (1931).
Parents:
Description: I couldn't find it.
CPD: N. (northiana x maxima) x ((gracilis x (rafflesiana x hirsuta)) x distillatoria).

gracilis x khasiana x rafflesiana
N. x lyrata

Bred and grown by William Court, Chelsea (Veitch Nurseries), UK, as of 1877.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Wilson) on The Gardeners' Chronicle ser. 2, vol. 8: 441 (1877) (description).
Parents:
Description: N. xhybrida x rafflesiana.
CPD: N. (gracilis x khasiana) x rafflesiana.
Macfarlane (1908): N. xhybrida x rafflesiana.

ampullaria x gracilis x khasiana x rafflesiana
N. x outramiana

Bred and grown by James Taplin, South Amboy, New Jersey, US, as of 1879.
Holotype: from material cultivated at Parker & Williams nursery, Holloway, UK (possibly held at herbarium K).
Name published by Parker & Williams nursery (validating description by Denny) on The Gardeners' Chronicle ser. 2, vol. 12: 505 (1879) (description).
Parents:
Description: N. xsedenii x xhookeri.
CPD: N. (gracilis x khasiana) x (rafflesiana x ampullaria).
Macfarlane (1908): probably N. xsedenii (N. distillatoria x sp. Borneo) x xhookeriana (N. ampullaria x rafflesiana).
Herbarium NHN-L specimens: link (year?), link (1906), link (1906), link (1906).

maxima x northiana x rafflesiana x veitchii
N. x picturata

Bred and grown by George Tivey, Chelsea (Veitch Nurseries), UK, as of 1903.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Gordon) on The Gardeners' Magazine 46: 670 (1903) (citation).
Parents:
Citation: N. xmixta x xdicksoniana.
CPD: N. (northiana x maxima) x (rafflesiana x veitchii).
Macfarlane (1908): synonym of N. x dyeriana.

gracilis x khasiana x veitchii
N. x rubromaculata

Bred and grown by William Court, Chelsea (Veitch Nurseries), UK, as of 1877.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Wilson) on The Gardeners' Chronicle ser. 2, vol. 8: 441 (1877) (description).
Parents:
Description: N. xhybrida x ?.
CPD: N. (gracilis x khasiana) x veitchii.
Macfarlane (1908): N. xhybrida x sp. Borneo.
Herbarium NHN-L specimen: link (year?).

distillatoria x gracilis x hirsuta x rafflesiana
N. x rufescens

Bred and grown by William Court, Chelsea (Veitch Nurseries), UK, as of 1888.
Holotype: from material cultivated at Veitch Nurseries (possibly held at herbarium K).
Name published by Veitch Nurseries (validating description by Maxwell T. Masters) on The Gardeners' Chronicle ser. 3, vol. 4: 669 (1888) (description).
Parents:
Description: N. xcourtii (N. xdominiana (N. rafflesiana x sp. Borneo) x sp. Borneo) x zeylanica.
CPD: N. (gracilis x (rafflesiana x hirsuta)) x distillatoria.
Macfarlane (1908): N. xcourtii (N. xdominii (N. rafflesiana x sp. Borneo) x sp. Borneo) x distillatoria var. rubra.
Herbaria NY and NHN-L specimens: link (year?), link (year?), link (1907), link (1907).

ampullaria x mirabilis x rafflesiana
N. x stewartii

Bred and grown by William Court, Chelsea (Veitch Nurseries), UK, as of 1879.
Holotype: from material cultivated at Glasnevin, Ireland (possibly held at herbarium DBN).
Published by Thomas Moore on Florist and Pomologist: 156 (1879) (description).
Parents:
Description: N. phyllamphora x hookeri (= N. rafflesiana).
CPD: N. mirabilis x (rafflesiana x ampullaria).
Macfarlane (1908): N. phyllamphora x xhookeriana.