Trichocereus glaucus – Echinopsis glauca
Trichocereus glaucus, also known as Echinopsis glauca, is a columnar cactus from Peru.
Trichocereus glaucus is a very interesting plant that is probably synonymous with some creeping varieties of Trichocereus peruvianus.
Origin: Peru ( Southern Peru ), Arequipa (Rio Tambo), Chile
Description: Trichocereus glaucus can get between 1,5-2 meters tall and is a creeping species that you oftenly find hanging down slopes and cliffs. This trait is very distinct in the variety Trichocereus glaucus var. pendens. The color of the skin is very glaucous and small specimens look absolutely like what was originally called Trichocereus macrogonus. However, macrogonus grows upwards while this species tends to bend over with age. New growth is very glaucous and gets even more glaucous later on.
Areoles: The areoles are dark brown to gray and are around 2,5 centimeters apart of each other. Similar to other San Pedro types, the plant has a diameter of up to 10 centimeters and the areoles are gray felted. The spines look a bit like the ones on Trichocereus cuzcoensis and are gray or brown. Trichocereus glaucus has 6-9 ribs, 3-6 middle spines and 8-11 radial spines. The middle spines are 5-10 centimeters and the radial spines 1-2 centimeters long. New spine growth is black to brown and turn gray with age.
Flowers: White, just like almost every other San Pedro cactus. The diameter is very variable and usually is between 15-22 centimeters. Trichocereus glaucus is a night-flowering species with green, round fruits. But the hairy flowers usually stay open until the next morning.
Fruit: Round, green, and 3 centimeters thick.
Location of the type: Lower part of the Rio Tambo in the department Arequipa.
Trichocereus glaucus is very similar to Trichocereus chalaensis and grows in a similar way. The plant was discovered by botanist Friedrich Ritter and his collection number is FR270. I gave away some seed of this plant a couple years in a row and I am looking forward to post more pics of them in the near future.
Seed & live cutting sources: I gave away seeds of Trichocereus glaucus a couple of years in a row and apart from that, I only know a couple more seed sources. Sacred Succulents has them every now and then & Köhres used to have some in stock too though I am not sure what type they will be. Trichocereus glaucus aka Echinopsis glauca is extremely rare and most plants on the market will probably come labeled as „Trichocereus peruvianus“ or „Trichocereus macrogonus“.
Cultivation: Trichocereus glaucus is a very resilient grower and likes to be watered well in summer. In winter, they should be kept as dry as possible at around 10° Celsius. Seed germinates very well and the plant is usually very tough. That´s also caused by its drought tolerance, which is very typical for Chilean plants. The plant will probably tolerate between -5° to -7° Celsius over very short time, but I would not stress it and this also depends on many other factors, like general health and dryness. I would recommend keeping at no lower than 10° Celsius in winter.
Varieties: Trichocereus glaucus var. pendens. This variety does only grow creeping down cliffs and small hills. This type only grows at one location in Chile and is extremely rare. This local population is in the south of Arica, Camarca in Chile. Backeberg suggested that this would be his Trichocereus Uyumpaensis, which is a creeping type of San Pedro too, but Friedrich Ritter vehemently disagreed with that.
Below: Trichocereus Glaucus – Fotos: Auxin
It forms shrubs with a size of 1 – 2 meters and often several meters in diameter, sprouting mainly from shoots that lay sideways on the ground. This plant rarely pups from the top or upper parts. The shoots are 5 – 8 inches thick, erect, later lying in the lower parts, the new shoot blue-green, later gray-green.
Ribs: 7-9, very broad, obtuse, 7.5 to 13 mm high, 15-25 mm wide, notched, with transverse furrows that do not reach down to the separating grooves of the ribs,
Areoles: grey felted, 1/2-3/4 inches in diameter, 1to 2 inches free removal, let down by the humps in the notches
Spines: In the new shoot black to brown, becoming gray, straight, rigid
Marginal spines: 7-10, directed laterally, the lower and lateral 8 to 15 mm long, coarse needle-shaped, somewhat flattened, the upper the upper stronger and not sharply separated from the Central spines.
Central spines: 3-6, very spread apart, subulate in the middle, but usually closer to the top edge and almost in the position of an edge of spine, below 1.5 mm thick
Flower: Not far from the apex, 13 to 19 centimeters long, fragrant, opening in the evening, the morning still open,
Ovary: Green with fleshy green, narrowly triangular, 2-5 mm long, pointed scales and large scales raised bases. The flowers are covered with brown/black hairs.
Partition against the nectar chamber 3-4 mm thick, tube-shaped, 13 to 23 mm long, to the stylus 1to 2 mm wide, brownish, almost openly, with nectar
Tubes: In addition funnel shaped, 40-65 mm long, the top 2 to 3 cm wide, pale green interior, exterior gray-green, with triangular points, 7.5 to 10 mm long, dark green scales and tufts of hair as on the ovary.
Stamens: white, greenish below, insertions missing on the top 2 to 3 centimeters of the tube to a ring on the hem, pouch pale brown, approximately at half height petals standing
Stylus: pale green, white or pale brownish above, 10 to 11 cm in length, with 14 to 18 mm fall on the 13-16 spread pale yellow stigma lobes, between the pouches or outstanding.
Deutsche Original Beschreibung:
Büsche von 1 meter bis 2 meter höhe und oft mehreren metern Durchmesser, sprossend hauptsächlich unten von liegenden Trieben, weniger oben sprossend. Triebe 5 bis 8 Zentimeter dick, aufrecht, später in den unteren Teilen liegend, im Neutrieb blaugrün, später mehr graugrün.
Rippen: 7-9, sehr breit, stumpf, 7,5 bis 13 mm hoch, 15 bis 25 mm breit, gekerbt, mit Querfurchen, die nicht bis zu den Trennfurchen der Rippen hinabreichen,
Areolen: Graufilzig, 1/2-3/4 Zentimeter Durchmesser, 1bis 2 Zentimeter freie Entfernung, , von den Höckern in die Kerben hinabreichend
Stacheln: Im Neutrieb schwarz bis braun, , vergrauend, gerade, starr
Randstacheln: 7 bis 10, seitlich gerichtet, die unteren und seitlichen 8 bis 15 mm lang, derb nadelförmig, etwas abgeflacht, die oberen die Oberen stärker und nicht scharf von den Mittelstacheln gesondert.
Mittelstacheln: 3 bis 6, sehr gespreizt, pfriemlich in der Mitte, aber meist näher dem oberen Rand und fast in der Stellung eines Randstachels, unten 1,5 mm dick
Blüte: Nicht weit weg vom Scheitel, 13 bis 19 zentimeter lang, duftend, abends öffnend, morgens noch offen,
Fruchtknoten: Grün mit fleischigen grünen, schmal dreieckigen, 2-5 mm langen spitzen Schuppen und großen erhabenen Schuppenbasen. Mit starken schwarzen oder braunschwarzen Wollhaaren.
Trennwand gegen die Nektarkammer 3-4 mm dick, diese tubisch, 13 bis 23 mm lang,um den Griffel 1bis 2 mm weit, bräunlich, fast offen, mit Nektar
Röhren: Darüber trichterig, 40 bis 65 mm lang, oben 2 bis 3 cm weit, innen blaß grünlich , außen graugrün, mit dreieckigen Spitzen, 7,5 bis 10 mm langen dunkelgrünen Schuppen und Haarbüscheln wie auf dem Fruchtknoten.
Staubfäden: weiß, unten grünlich, Insertionen fehlen auf den obersten 2 bis 3 Zentimetern der Röhre, bis auf einen Ring auf dem Saum, Beutel blassbraun, etwa bei halber Petalen Höhe stehend
Griffel: blassgrün, oben weiß oder blass bräunlich, 10 bis 11 cm lang, wovon 14 bis 18 mm auf die 13-16 gespreizten blaßgelben Narbenäste fallen, zwischen den Beuteln oder sie überragend.
Very interesting Plant and very similar to what some would label Trichocereus Macrogonus.
Trichocereus glaucus - Echinopsis glauca
Emőke Dénes Echinopsis_smrziana_-_Kew_Gardens 
Oslo Sukkulentforening Soehrensia_smrziana
