GENUS PACHYPHYTUM

By James E. Low

This is a small genus of plants found in Mexico & descended from the Sedums. With the new discoveries in recent years there are now about 20 valid species. The lines of its evolution are not clear, but may involve the Echeveria line in some way. Genus Pachyphytum is now classified in subfamily Echeverioideae, but new research involving DNA sequencing may result in some reclassification in the next few years. The meaning of the Latin word pachyphytum is “massive plant” which is true for these species in both leaf and stem. Most species are fertile to most Echeverias and to some Sedums and other species in related genera. This implies a close evolutionary relationship. Some of the “intergeneric hybrids” are beautiful and have become popular in the nursery trade in many countries. They are easy hybrids to prepare in the lab, but few (if any) hybrids ever occur in nature.

The genus was erected in 1841 by Klotzsch for the first known species, P. bracteosum that had confused classifying botanists, resulting in some of them placing it into some odd genera. Lindley and Paxton in 1853 wanted it in Echeveria. Sir J. Dalton Hooker with Bentham placed it (and the Echeverias) into the European catchall genus Cotyledon, but this was soon ignored as it was obviously not closely related. This first species has a large calyx with very unequal sepals, and the base of petals were folded inward, making a distinct characteristic for the genus. Later species have some of these characters less pronounced: but all have the unique lobed petals and thick leaves and solitary cincinni with pendant flowers and appressed calyx. Every species is native only within Mexico. Read some history of these plants by Moran in CSSA Journal of May, 1989 on page 119-120. More recently Charles Glass found and studied a few more species just before he died, but these were later described and published and do appear in the list below. Most Pachyphytum are of easy culture.

Moran has divided this genus into 3 divisions, naming the sections as follows

Sect. 2 is Ixiocaulon with 2 species.

Sect. 3 is Diotostemon with 4 species.

(The section placement of each species in the list below is indicated by these numbers shown above being included, following the species name).

Note: In the I.O.S. Lexicon volume on Crassulaceae of 2003 author J. Thiede listed the sections of genus Pachyphytum as only Sect. 1 & Sect. 3, leaving out Sect. 2. (Section Ixiocaulon was not listed, but without any explanation). We would like to know why and if botanist Reid Moran was consulted. Perhaps someone will have an answer.

 

PACHYPHYTUM SPECIES LISTINGS

aduncum, (Sect. ?); [B&R, 1903], “from Mexico”: This species is now lost, and little is known; but most likely is not a valid species. It may have been a form of what is now called P. hookeri. Read page 236 of CSSA Journal of Sept, 1990. Name means ?

*status uncertain.

BRACHETII (Sect. 1) [Reyes, Gonzales & Gutierrez, 2007] This is a species nova published in the Mexican Cactus and Succulent Journal, 52(2), 2007. It comes from east-central Mexico in the state of Hidalgo near Actopan where it grows hanging from vertical walls in just one known location. It was discovered by Jeronimo Reyes in April 2000 at an elevation of 2200 meters. It is named to honor Sr. Christian Brachet Ize for his contribution to the knowledge of genus Pachyphytum and other genera of family Crassulaceae. This new species is related to P. bracteosum, P. garciae, and P. caesium from which it differs in color and size of the calyx, corolla and pedicels, as well as the color, texture and size of the stem. This species has leaves typical of Sect. 1 species, but a bit larger, and in larger rosettes, on thicker stems. Refer to the Mexican Cact. y Suc. Journal cited above for details and color photos.
=Pachyphytum brachetii [Reyes, González & Guitérrez, 2007], current.

BRACTEOSUM, (Sect.1), [Klotzsch, 1841], E. Cent. Mex., n=33, 66, fl. red. Read CSSA Journ. of May, 1991, page 119. This Latin species name refers to the bracts (tiny leaves between the flowers) that it bears.

=*Pachyphytum bracteosum, [Link, Klotzsch & Otto, 1841], current.

=Echeveria bracteosa, [Lindley, 1853], obs.

=Cotyledon pachyphytum, [Bak., 1853], obs.

=Echeveria pachyphytum, [Morren, 1874], obs.

BREVIFOLIUM, (Sect. 1), [Rose, 1905], Cent. Mex., Note: this species was lost to cultivation for over a century, but was recently rediscovered. Old details by Moran: in CSSA Journ. of Jan. 1991, pages 32-33. Name means, “having short leaves”. The new plants were fully re-described in Spanish by the Mexican botanist Meyran and a copy is in my notebook awaiting translation: this includes a fine line drawing. The new plants were found in 2 localities listed in the re-publication papers from Acta Botanica Mexicana (1999), 48:1-10.

=*P. brevifolium, [Rose, 1905].

CAESIUM, (Sect.1), [Kimnach, 1993], Cent. Mex., n=31, flowers light orange. The Latin species name refers to the habitat location. It was found in a canyon with the Spanish name of “Arroyo Agua Zarca” that means “bluish water canyon” and in Latin this color is called “caesium”. It is in the Mexican state of Auascalientes (state of the “hot waters”). Local people told visiting botanist B. Baker about the plants and led him to them. He brought some back for study in 1989 for Kimnach and Moran. They published it in CSSA Journ. of March, 1993 on page 59 with fine photos.

=*P. caesium, [Kimnach, 1993].

COERULEUM, (Sect.3), [Meyran, 1963], E. Cent. Mex., n=31, flowers yellow. Unknown in the wild. The Latin species name refers to the bluish color of the frosted leaves. This is a small plant with rosetted leaves like an Echeveria, and the flowers also resemble Echeveria flowers; thus this species is indeed closely related to the Echeverias. Details of the flowers places it just marginally within genus Pachyphytum.

=*P. coeruleum, [Meyran, 1963].

 

 

COMPACTUM, (Sect.3), [Rose, 1911], E. Cent. Mex., flowers orange; n=31, 62, 124, 186. Latin name refers to small size of the plants. Read CSSA Journ. of Jan. 1991, page 30. Discovered by C. A. Purpus in 1911, but never seen again in spot he gave as the habitat. Cultivated plants must be from Purpus first collection, but recently it was rediscovered in the wild, but this time in a different state.

=*P. compactum, [Rose, 1911].

 

 

CONTRERASII, (Sect. #1), [Glass, 1998], W. Cent. Mexico (near the 2nd largest city of Mex. and in a popular tourist canyon). Glass told of this species in the last letter he wrote before he died. This is one of 3 new Pachyphytums Glass was studying for publication at that time (the others being P. garciae & P. machucae). He never even explained the names meaning. Glass was a long time editor of the CSSA Journ., later making Mexico his home. It is not even sure he published any of these species properly. Now awaiting more details. Everything about this “species nova” is clouded by strict new regulations about native plants by Mexico. Uhl was hoping to test the chromosomes, but may never have gotten live material yet to test. Maybe now we can find its status as listed in the 2003 Lexicon. Probably in time plants will be made available by the Mexican authorities.

=*P. contrerasii, [Glass, 1998], current (?) still unpublished in late 2003.

FITTKAUI, (Sect. 2), [Moran, 1971], from Guanajuato state in Mex., n=66, 93-96; flowers red. Named to honor Catholic Father (Padre) Hans Fittkau who loved succulent plants and was great help in finding them in the wild for botanists. This is one of the tallest species of the genus, stems often go prostrate. Flower clusters are over a foot tall! Published in CSSA Journ. 43:26-32 (1971). See photo in Mexican C&S Journ. of Jan. 1994, page 13.

=*P. fittkaui, [Moran, 1971], current.

 

 

 

GARCIAE, (Sect. #1), [Glass, Perez-Calix, 1999], this new species from Queretaro state was named for its discoverer: Juan Antonio Garcia Luna. The habitat is listed as Que., about 4 km NW of Rio Blanco, Municipio Penamiller growing at 1600 meters altitude. This is the 2nd of 3 new species (along with P. contrerasii) Glass was about to publish just before he died in 1998, but was published later with his name. A copy of the publication papers in Acta Botanica Mexicana 1999. 48: 4-7 can be found in my notebooks (in Spanish) with a fine line drawing.

=*P. garciae, [Glass & Perez-Calix, 1998].

GLUTINICAULE, (Sect 2), [Moran, 1963], E. Cent. Mex., n=33, 66, 99; flowers light red in clusters of 6 to 20. Latin name means “glue-stem” in reference to its thick sap. This species was ISI 92-57 offered in CSSA Journ. of Mar. 1992 on p.89. The leaves of this species somewhat resemble those of the popular P. oviferum, but differ in having tiny, sharp tips, and top surface is more flat. Like most species in this genus new plants are easily grown from detached leaves.

=*P. glutinicaule, [Moan, 1963], current.

 

 

 

HOOKERI, (Sect. 3), [Salm-Dyck, 1854], NE Mex., n=32, 64, 92, 128, 160; flower color (?). Name honors Sir W. J. Hooker 1854 director of Kew Botanical Gardens in London. Salm Dyck knew of genus Pachyphytum, but the scales of this plant did not let it fit in, so he made a new genus, but in time it had to be moved to Pachyphytum and his special genus dropped. Read total history of this species by Moran in CSSA Journ. of Sept. 1990, pages 236-241 with good photos.

=Diotostemon hookeri, [Prince Salm-Dyck, 1854], obs.

=Echeveria hookeri, [Lemaire, 1863], obs.

=Cotyledon adunca, [Baker, 1869], obs.

=Pachyphytum uniflorum, [Rose, 1903], obs.

=Echeveria adunca, [Otto, 1873], obs.

=Pachyphytum uniflorum, [Rose, 1903], obs.

=Pachyphytum aduncum, (Rose, 1905], obs.

=Echeveria uniflora, [Berger, 1912], obs.

=*Pachyphytum hookeri, [Berger, 1930], current.

KIMNACHII, (Sect. 1), [Moran, 1967], NE Mex., n=33, flowers pink. Name honors Myron Kimnach, editor of CSSA Journal. See p. 200 of this journal for year 1997 for details.

=*P. kimnachii, [Moran, 1967], current.

 

LONGIFOLIUM, (Sect.1), [Rose, 1905], E. Cent. Mex., n=33, 66, flowers red. Name means “long leafed”. See CSSA Journ. of Sept. 1991, p. 261 for details.

=*P. longifolium, [Rose, 1905], current.

MACHUCAE, (Sect.?), [Ruiz, Chazaro & Glass, 1999], a new sp. from NW Michoacan state in central Mexico. [Note: a new Sedum has a related name (S. machucana) from near same habitat, and found by some of the same explorers in about same year, so care must be taken not to confuse the two names]. This is a 3rd Pachyphytum sp. that was being studied by Mr. Glass just before his 1998 death; he called it a “beautiful new species”. It forms a lovely leaf rosette. This species was published in the new Mexican botanical journal “Acta Botanica Mexicana” in (1999) 47: 9-14, pages 9 to 14 (in Spanish). Named for a village nearest the habitat.

=*P. machucae, [Ruiz, Chazaro, & Glass, 1999], current.

OVIFERUM, (Sect.1), [Purpus, 1919], NE Mex., n=33, flowers green & white. Note: this species is the most common Pachyphytum in cultivation today. It is beautiful, and of easy culture. Note: this species (and the new P. saltensis) can easily be confused with Graptopetalum amethystinum when not in flower, but in flower there can be no mistake as the flowers are so very different. Despite the amazing physical similarity of the leaves and stems, the line of evolution would have to be entirely different, of course (a sort of parallel evolution).

=*P. oviferum, [Purpus, 1919], current.

RZEDOWSKII, [Garcia, Perez-Calix & Meyran, 2002], (Sect. 1), leaves semi-terete; this is a new species close to P. machucae, but differing in size and shape of leaves, length of pedicels, and color of the petals. This species and P. machucae are the only species of this genus from the state of Michoacan, but their habitats are about 200 km apart, with machucae in NW Michoacan, and this species found in east-central part just south of the Trans-Mexican Volcanic Belt in the “Balsas Depression”. Published in the Anales del Instituto de Biologia, Universidad Nacional Autonoma de Mexico, Serie Botanica 73(2): 147-153, 2002. A copy of these papers can be found in my notebook with English resume. This species name honors a lady: Graciela Calderon Rzedowski, wife of Dr. Jerzy R., a professor and researcher, long active in species preservation of Mexican plants.

=*P. rzedowskii, [Garcia, Perez-Calix & Meyran, 2002], current.

SALTENSIS, (Sect. 1), [Brachet, Reyes & Mondragon, 2006] N. central Mexico, in Zacetacas state, in El Salta Canyon; This species nova resembles a species in genus Graptopetalum, but is in reality a species of Pachyphytum! (The same is true of P. oviferum): the difference can be seen in the flowers: each species has flowers typical of its genus. Vegetatively this species resembles the well known G. amethystinum, especially in the shape and coloration of the leaves. The flowers are dull white with a large spot of red in the middle. The plants grow hanging from the canyon walls of one canyon. This new species was published in the Mexican C&S journal: “Cact. y Succl. Mex.” 51 (2): 46-51.

=*P. saltensis, [B. R, & M, 2006], current.

uniflorum, [Rose, 1903]. Note: this species is no longer recognized because study showed it to be just an extreme form of P. hookeri (listed above). A Dr. Palmer in Mexico became fascinated by these plants and called them to the attention of US Botanists, who studied them and named and published them. Palmer lived in the city of San Luis Potisi, and he became intrigued by these interesting plants which he saw so many people growing in the courtyards of their villas. So, he investigated and found they grew wild in the canyons just outside the city. Read details on p. 236 of the CSSA Journal of Sept. 1990. He supplied plants to Dr. Rose for study.

=*P. hookeri, [Salm-Dyck, 1854], current.

VIRIDE (Sect. 1), [Walther, 1937], E. Cent. Mex., n=33, flower color (?). Species published in CSSA Journ. of 1937 (8-210). Excellent article by Moran in CSSA of Mar. 1992 with photos. BW photo of blooming spike CSSA of May, 1991, p.118. Latin name of species means, “green” and refers to leaves of a light green with no frosting. This is also the largest species of the genus.

=*P. viride, [Walther, 1937], current.

WERDERMANNII, (Sect.?), [Poellnitz, 1937], NE. Mex., n=33, flowers bright pink, with a deep crimson blotch of color at one spot. Long, creeping stems; leaves fleshy and a bit wrinkled, light green. Plants have become widely available in recent years.

=*P. werdermannii, [von Poellnitz, 1937], current.

 

 

 

Pachyphytum hybrids.

Some hybrids are popular today. X Pachyveria ‘Elaine’ was ISI-876 in 1974. See photo of it on p. 235 of CSSA of Sept. 1990. Another one is ‘Blue Haze’. Prof. Uhl made and favours his hybrid of fittkaui x compactum. Still another is x Pachyveria ‘Haagei’ that was widely sold in the mid 1990s. Flowers of the hybrids often look much like Pachyphytum species blooms.