Synonymy

Epiphyllum crenatum v. crenatum
Cereus crenatus Lindl. (1844) Bot. Reg. 30: t 31
Phyllocactus crenatus (Lindl.) Lemaire (1845) Hort. Univ. 6:87
Phyllocactus caulorrhizus Lemaire (1851) Jard. Fleur 1: misc. 6
Epiphyllum crenatum (Lindl.) G. Don in Loudon (1855) Encycl. Pl. ed 3. 1378
Epiphyllum caulorrhizum (Lindl.) G. Don in Loudon (1855) Encycl. Pl. ed 3. 1380
Epiphyllum chichicastenango hort.
Epiphyllum kinchinjunga hort.
Phyllocactus hildmannii hort.
Phyllocactus wrayi hort.

Epiphyllum crenatum v. kimnachii
Phyllocactus cooperi Regel (1884) Gartenflora 33:357
Phyllocactus pfersdorfii hort.
Epiphyllum cooperi (Regel) Clover in L. H. & E. Z. Bailey (1941) Hortus Second. 281
Epiphyllum pfersdorfii (hort.) Clover in L. H. & E. Z. Bailey (1941) Hortus Second. 281
X Seleniphyllum cooperi (Regel) Rowley (1962) Die Cactacee 6:3557 pro parte, nom. illeg.
Marniera macroptera v kimnachii (Bravo) Backeberg (1966) Das Kakteenlexicon 450

Ethymology
Crenatum (lat.) = with crenations. Refers to the crenated stem margins. The variety kimnachii honours Dr. Myron Kimnach, well known botanist, mainly working with epiphytic cacti and Crassulaceae.

History
This species was shown at an exhibition at the Horticultural Society's Garden in 1844 and won highest medal for a new introduction. It had been collected in Honduras 5 years earlier by Georges Ule Skinner and sent to Sir Charles Lemon who flowered it for the first time in 1843.
Lindley thought it to have originated in the island of Antigua.

E. crenatum is the only species of Epiphyllum that has been used in hybridization to any extent. Most of the colored hybrids have mainly Disocactus genes and perhaps better refered to as Disocactus-hybrids rather than Epiphyllum hybrids.

E. crenatum v. kimnachii 'Cooperi' Photographer unknown

Comments by Dr. Myron Kimnach

I worked in botanical gardens for many years, 11 at UC Berkeley and 25 at the Huntington. At Berkeley in the 1950s Paul Hutchison (the botanist) and I (the grower of the succulent, fern and orchid collections) built up a large
collection of epiphytic cacti there. I corresponded with Charles Lankester and Clarence Horich of Costa Rica and they both sent many species to UCBG. I published some of them as new species or wrote about those that were very little known. I went to the Huntington in 1962.

Epiphyllum cooperi.
It's a complicated story, and, unfortunately, the two articles that relate it are not very well known. In 1964 a Mexican botanist, Helia Bravo, described Epiphyllum crenatum var. kimnachii, listing many wild herbarium collections from Oaxaca and Chiapas. I also collected many of these plants in Mexico and studied many collected by Thomas MacDougal. These all differed from var. crenatum in having many small bracts with spines at the base of the flower and the outer petals emerged for some distance below the apex of the flower. Var. crenatum (Mexico through Honduras) on the other hand had only a few bracts and no spines at the base of the flower and the outer petals all originated at the apex of the tube.
'Cooperi' (known only from cultivation) differs from var. kimnachii only in having the outer petals at the apex of the tube. It was originally claimed that 'Cooperi' was a hybrid between an Epiphyllum and a Selenicereus, but in 1997 an article was published in Haseltonia by Metz, Fröhlich, Kimnach & Meyerowitz that reported that through DNA analysis it had been shown that there was no trace of Selenicereus in 'Cooperi'.
The plants used in this test were the original clone of 'Cooperi', wild forms of var. kimnachii and var. crenatum, and two species of Selenicereus. So definitely the name  X Seleniphyllum must be dropped. One has a choice of several names for 'Cooperi'. First, it is only a minor variant of var. kimnachii and is only known from cultivation, so in my opinion it's best to give it cultivar status as E. crenatum var. kimnachii 'Cooperi'. That's a long awkward name and one can of course call it Epiphyllum cooperi, but that name is not likely to be accepted botanically
ue to the close relationship with E. crenatum.

Myron Kimnach

Clive Innes stated that he "re-made" the cross between E. crenatum and Selenicereus grandiflorus, obtaining several plants identical with 'Cooperi',  supporting the theory that it is in fact a hybrid. However, he never managed to present any of those.

Clive Innes, unfortuntaly, did mixup facts on several occations in the past making his reports somewhat doubtful.

E. crenatum v. crenatum  Photographer unknown

E. crenatum v. crenatum 'Chichicastenango'
Photograph by J. F. Horobin

E. crenatum v. crenatum. Photographer unknown

Description

E. crenatum var. crenatum

Stem erect to ascending, profusely brached, primary stems terete or 3-angled for a short portion at base, becoming ligneous, flat at most of their length, secondary stems flat, flattened portions to 60 cm long, to 6-10 cm wide, stiff and rather succulent, lanceolate to long linear, acute or obtuse, median nerv rather thick, margins deeply or coarsely crenate, lobes oblique; areoles at the bases of stems sometimes bearing hairs or small bristles, internodes narrow or broad; epidermis green or almost greyish green, smooth.
Flowers to 20-29cm long and 10-20 cm wide, nocturnal but remaining open for several days, fragrant; pericarpel 5-angled, with acute, long-decurrent podaria, bracteoles subtening 0-2 (-8) spines to 7 mm long,, green; receptacle 10-12 cm long, green often reddish at apex or reddish throughout, bearing numerous linear to oblong, obtuse bracleoles 2-3 cm long, more or less spreading; outer tepals inserted within 2 cm of receptacle apex, 10-12 cm long, broadly linear, greenish yellow to tawny yellow, the outermost sometimes margined red or straked; inner tepals as long as outer, spathulate to oblanceolate, white, creamy white or greenish yellow; stamens shorter than tepals, numerous, declinate, pale yellow; style and stigma white, lobes 8-9, papillose.
Fruit oblong to globose, the podaria long decurrent, acute.

E. crenatum v. kimnachii

Differs from the typical cariety by: stems 4-6 cm wide, lobes usually semicircular; pericarpel and receptacle subterete in cross-section; pericarpel with sunconical or obtuse, shortly decurrent podaria and with bracteoles subtending ca 6 (0-20) spines to 12 mm long; outer tepals usually inserted within 4-8 cm of tube apex; fruit globose, the podaria shortly decurrent, obtuse.

Origin and habitat
Mexico (Oaxaca & Chiapas) to Honduras. Epiphytic or lithophytic in moist or wet forests, sometimes in oak forests. 1.750 m alt. or less.

Systematics
This species is very distinct and its nearest relative are E. lauii and E. anguliger. The flowers of E. grandilobum is similar but the stem morphology is very different. E. macropterum probably refers here, but due to lack of type material its identity will never be known. The name must be rejected.

Cultivation
An easily cultivated, fast growing epiphyte. Needs a compost containing plenty of humus and sufficient moisture in summer. Should not be kept under 12ºC (53,5ºF) in winter. Can be grown in semi-shade or full sun. Extra light in the early spring will stuimulate budding. Flowers in late spring or early summer.

E. crenatum v. crenatum 'Wrayi'. Blühende Kakteen

Cultivars and hybrids
X Disophyllum amarantina ´Amarantina'
( Disocactus ackermannii x E. crenatum)

X Disophyllum amarantina 'Coopermannii' 1901
(Disocactus ackermannii x E. crenatum v. kimnachii)

X Disophyllum amarantina 'Helenae' (1901)
(Disocactus ackermannii x E. crenatum v. kimnachii)

X Disophyllum charltonii 'Grand Soleil' (FAW 1845)
(Aporocactus flagelliformis x E. crenatum .)
Scarlet and golden yellow tepals edged in violet and fire red.

X Disophyllum splendens ´Roseus Grandiflorus'
(Disocactus phyllanthoides x E. crenatum)

X Disophyllum splendens ´ Splendens' (1861)
(Disocactus phyllanthoides x E. crenatum)

X Disophyllum splendens ´Vogeli' (1861)
(Disocactus phyllanthoides x E. crenatum)

X Disophyllum 'Canadian Ruffles' (Denn 1954)
(E. crenatum v. kimnachii 'Cooperi' x unknown.)
Outer tepals orange; inner tepals violet with orange midstripe. XL

X Disophyllum 'Donald Duck' (Bhm)
(E. crenatum  x unknown)
A white flower that begins as a black bud.

X Disophyllum 'Grace Marie' (Bhm 1949)
(E. crenatum v. kimnachii 'Cooperi'  x unknown)
Wide open flower of delicate true pink, oter tepals dusky pink. Similar to 'Cooperi´.

X Disophyllum 'Haageanus' (FAW 1845)
(E. crenatum  x unknown)
Clear orange.

X Disophyllum 'Junga' (CP 1945)
(E. crenatum 'Kinchinjunga'  x unknown)
Intense dark red coloring with extra wide inner tepals. The funnel-shaped flower is very fragrant and considered a late bloomer. XL.

X Disophyllum 'Letty May' (TMM/Cox )
(E. crenatum x 'Curt Backeberg´)
Dark variegated yellow-orange with the inner tepals edged in violet. Bowl-formed. L.

X Disophyllum 'Maryland' (CP 1948 )
(E. crenatum 'Kinchinjunga' x unknown)
A wide open cup of burnt orange tepals. XL.

X Disophyllum 'Paradise Queen' (Bhm 1951)
(E. crenatum v. kimnachii 'Cooperi' x unknown)
One tone fuchsia pink with an electric blue overcast.

X Disophyllum 'Phyllocereus Roseopurpureus' (1931)
(Disocactus ackermannii x E. crenatum v. kimnachii x Disocactus speciosus)

X Disophyllum 'Regalia' (Shuey 1947)
(E. crenatum x 'Hermosissimus')
Red-violet tepals opening very wide and large

X Disophyllum 'Rother Cooperi' (D)
(E. crenatum  v. kimnachii x unknown)
Red tinged violet, similar to 'Cooperi'.

X Disophyllum 'Vanity' (CP 1954)
(X Disophyllum 'Canadian Ruffles´x unknown)
Exceptional beautiful bloom of soft orange, ruffled on the edges with a trace of red coloring. Form and style very similar to the parent. XL.

X Disophyllum 'Victoria Regia' (WOR)
(Disocactus x vandesii 'Ackermannii' x E. crenatum v. kimnachii 'Pfersdorfii')
Outer tepals yellow, inner tepals white.

X Disophyllum 'Westwood Vision' (WC 7x5/hawks 1977))
(E. crenatum  v. kimnachii 'Cooperi' x 'Curt Backeberg')
Nice flaring funnel bloom of v'cream colored inner tepals and lemon yellow outer tepals. Long.

Epiphyllum 'Grief' (RWP)
(E. crenatum  x 'Eden')
White throughout. ML

Epiphyllum crenatum 'Americanus'

Epiphyllum crenatum 'Chichicastenango'
Form with mutated stems, lobes or margins often missing at one side of the midrib. Flowers as in var. crenatum. Originally from Guatemala.

Epiphyllum crenatum 'Deutchland' (Knebel)
Very similar to 'Cooperi'

Epiphyllum crenatum 'Hildmannii'

Epiphyllum crenatum 'Kinchinjunga'
Collected by C. A. Purpus in Oaxaca, Mexico.

Epiphyllum crenatum 'Stella' (Haage 1938)
Very similar to the vild form.

Epiphyllum crenatum 'White Queen' (Joseph Passmore)
(E. crenatum v. crenatum x E. crenatum v. kimnachii)
Creamy white, very fragrant.

Epiphyllum crenatum 'Wrayi' (FAW 1845)
Innter tepals white, outer tepals browna and yellow. Very fragrant.

Epiphyllum crenatum  v. kimnachii ' Albus Perfectus' (FAW 1845)
Creamy white. Very similar to 'Cooperi'

Epiphyllum crenatum v. kimnachii 'Albus Perfectus Superbissimus' (FAW 1845)'
White with a yellow trim. Very similar to 'Cooperi'. L.

Epiphyllum crenatum v. kimnachii 'Albus Superbus'
White throughout. Very similar to 'Cooperi'. L.

Epiphyllum crenatum v. kimnachii 'Beligica' (Laet)
Very similar to 'Cooperi'

Epiphyllum crenatum v. kimnachii 'Cooperi' (FAW. 1845). Outer tepals yellow; inner tepals white, fragrant. L. Flowers near base of stems.

Epiphyllum crenatum v. kimnachii 'Meyerianus' (1905)

Epiphyllum crenatum v. kimnachii 'Pfersdorfii' (FAW 1845)
Outer tepals yellow; inner tepals white, fragrant. Flowers not near the base of stems.

Epiphyllum crenatum v. kimnachii 'Tettaui' (Haage)
Outer tepals purpulish, innter white. Stems more robust than in 'Cooperi'.

Epiphyllum 'Mount Lofty' (Bhm)
(E. crenatum x unknown)
Crimpy, semi-rounded creamy inner tepals surroundd by yellowish green outer tepals.

Epiphyllum 'My Own' (Weg)
(E. crenatum x unknown)
Creamy inner tepals with a slight green cast. large.