You won’t find a blue-flowered cactus—the entirely family Cactaceae famously lacks blue flower pigment. Green cactus flowers, however… while not common, green cactus flowers do exist, for instance on this week’s South American cactus, Gymnocalycium leeanum.

As it matures, this Argentina cactus often forms clumps of several round bodies. Its central spines (outward-facing spines) may be lacking, as in the pictured specimen. The radial spines are held close to the round body, as if ironed flush to the cactus’s outer surface.

Gymnocalycium leeanum flowers range from yellow, yellow-white, or greenish yellow, as in the plant pictured.

Gymnocalycium leeanum, grown and photographed by Mr Sentient Meat

Bolivian cactus Rebutia neocumingii was known under genus name Weingartia from its description by Backeberg in 1950 until Weingartia was combined under Rebutia by Hunt in 1987. Its flowers can be yellow, orange or red depending on locality. It’s normally solitary and unbranched, though the individual pictured is sprouting additional heads. Typically this species has much longer spines; this plant was obtained as form brevispina. It is about 7.5 cm across; at full growth, it can reach 10cm across and up to 20cm in height.

Turbinicarpus valdezianus is one of the smallest and slowest-growing cactus—small even within genus Turbinicarpus, not known for their tremendous size. The diminutive body is the size and shape of a thimble. The spines are minute, almost microscopic, and flattened against the body in harmless tight formation—more like scales than armament. Flowers are pink, often striped; occasionally white.

Turbinicarpus valdezianus is found in Coahuila, San Luis Potosí, Nuevo León, and Zacatecas.

Turbinicarpus valdezianus showing more of body

Correction: The plant was originally identified as Turbinicarpus valdezianus. A fallen label was discovered, and this plant is the related Turbinicarpus pseudopectinatus.

This week Parodia buiningii takes us to South America. Each plant is an excuse to learn more about botany and geography, bouncing from continent to continent as the inspiration strikes. A succulent species represents millions of years of adaptation to specific ecological pressures in Mexico or the rest of North America, Africa, Madagascar… or this week, Uruguay and Brazil.

Parodia buiningii is also known by its synonym Notocactus buiningii. (All Notocactus species have been included under the genus Parodia, where they form a distinct clade: a group of related plants with evidence of descending from a common ancestor.) 

Parodia buiningii is one of the most handsome members of the group formerly known as genus Notocactus: geometric ribs, glaucous blue-green skin, and needle-sharp spines the color of tortoise shell. This Parodia buiningii has advanced flower buds with characteristic brown wool. They look almost like fuzzy antlers on a young deer or strange rabbit ears. The flowers will be yellow. This individual is probably a few years old and measures approximately 3 inches across.

Notocactus buiningii grown and photographed by Mr Sentient Meat

Which country is it really from, you ask—Uruguay or Brazil? Well, Parodia buiningii is found near the unusual dual-nationality city: Rivera, the capital of the Rivera Department of Uruguay and (Santana do) Livramento, a city in the state of Rio Grande do Sul, Brazil. In an uncommon arrangement, citizens of either country within the city can cross the border freely. Customs and checkpoints are located outside the city.

Parodia buiningii is reportedly rare in its habitat, the environs of these twin cities, Rivera, Uruguay, and Livramento, Brazil.

Closeup of same Notocactus buiningii grown and photographed by Mr Sentient Meat

Called “brain cactus”, the genus Stenocactus hails from Mexico. It’s distinguished by its wavy ribs. Also called Echinofossulocactus, this genus varies widely in size, spination, and number of ribs.

Today’s species, Stenocactus multicostatus (“many-ribbed”) enjoys wide distribution in Mexico: Chihuahua, Coahuila, Durango, Nuevo Léon, San Luis Potosí, and Zacatecas. True to its name, it seldom has fewer than 120 ribs. Notice the flat, stout central spines.

Stenocactus multicostatus

Within that natural variation, this individual shows flowers typical of stenocactus: short, funnel- or bell-shaped; white with purple-pink midstripe.

Stenocactus multicostatus flowers seen from above

See Also

Stenocactus multicostatus at Cactus-Art.Biz

Even if you limit yourself to the most seductive cacti from genus Mammillaria, you still have dozens of strange and wonderful plants to choose from. Mammillaria pectinifera (Latin for “comb-bearing”) has such minute, harmless spines that they appear like legs on tiny bugs—reminiscent of the spines on Mammillaria hernandezii (profiled previously). The spine beds are elongated vertically, like so many miniature millipedes marching in tight formation.

Surprisingly, Mammillaria pectinifera is most closely related to M. carmenae (which looks completely different; also profiled on Sentient Meat), M. glassii, M. picta, M. plumosa, and M. prolifera. Together these species plants form a clade, a group of types likely descending from a common ancestor. They differ markedly from each other in size, spines, and other features.

Mammillaria pectinifera, endangered miniature cactus native to Puebla, Oaxaca. Plant grown and photographed by Mr Sentient Meat

My plant is just over an inch in diameter. This is its first bloom under my care. The flowers are an elegant pale pink. Overall the plant is neat and understated in appearance.

Mammillaria pectinifera, same plant viewed close up, plant grown and photographed by Mr Sentient Meat

Mammillaria pectinifera‘s appeal may be its downfall. It has reportedly been collected nearly to extinction within its native Puebla, Oaxaca, Mexico. Consequently, it’s protected under CITES I, the most stringent protocol of international protection.

Like last week’s copiapoa, this week’s eriosyce comes from Chile on South America’s arid Pacific coast. Eriosyce senilis ssp. senilis has long, curly white spines resembling a scraggly old beard. It hails from the Rio Choapa valley in the Coquimbo region of Chile.

Eriosyce senilis starting full bloom

This individual has a dark maroon body—about 3 inches wide—which contrasts strongly with the long, white spines. Frilly shocking-magenta flowers emerge like trumpets.

Eriosyce senilis flower closeup

February, 2012, is too mild in Southern California to be called “the dead of winter”. While some plants have slowed down drastically, others have reawakened and are pushing new flower buds. My Copiapoa tenuissima is pictured in full bloom with yellow flowers sharply contrasting against the dark maroon body.

In early February, the most active cacti and succulents are plants from regions with winter rainfall (or fog), typically near western coasts. Copiapoa tenuissima follows this general rule since it comes from around Chile’s Pacific Ocean (western) port city of Antofagasta.

Look at the 10 or 11 new heads branching off from the central body. These can be re-rooted and grown as new plants, though it takes a while for a detached head to grow new roots.

The currently accepted name is Copiapoa humilis subspecies tenuissima, since the original description of Copiapoa tenuissima was invalid. I’m mildly dissatisfied with this classification for sentimental reasons: Copiapoa humilis is a rough and lumpy species which grows fast and messy. By contrast, this Copiapoa tenuissima seems to be rather elegant.

See Also

Hunt, David. 2006. The New Cactus Lexicon. dh books. The Manse, Chapel Lane, Milborne Port, Sherborne DT9 5DL, England.

If you were marooned on a… ahem… DESERT island and could only grow one genus of cactus… okay humor me here… don’t you think it would probably be…

Mammillaria

Mammillaria is a large genus with about 140–180 species, depending on who’s listing them. So if you’re stuck on that hypothetical desert island, you won’t be limiting your options very much.

Pilbeam (1999) recognizes 181 Mammillaria species and of these Hunt (1999) accepts 145. Any way you split this genus, it is one of the most varied in the Cactaceae, and it also has wide distribution: southward as far as Colombia and Venezuela and northward extending into the American Southwest. The greatest richness and diversity of Mammillaria varieties is in Mexico.

Mammillaria carmenae is native to Tamaulipas, Mexico.

Mammillaria carmenae, a particularly blonde and pink-flowered individual cared for and photographed by Mr Sentient Meat. Spines can vary from yellow to white. Flowers can be white, pink or pink-tinged white.

Mammillaria is a very diverse group; however none of these cacti are giant trees. They are all small-to-medium-size “globular” (roundish) cacti. Some are solitary; others grow into large clumps. They all have distinctive bumps which remind scientists of breasts enough to earn the name mammillae—thus the genus name (or as they say in the lingo, the generic epithet).

Mammillaria carmenae, same plant, different angle

The plant pictured is fully grown at around 3 inches tall and 2 inches in diameter. This species is known to grow in clusters, so it’s probably time for me to move it to a larger pot where it can spread out and grow more bodies.

Mammillaria carmenae has pale yellow to white spines, and each areole (at the tip of each mammilla) has over 100 spines, obscuring the surface of the plant almost entirely. It reminds me a bit of Mammillaria candida (profiled recently) or Mammillaria lasiacantha (in the collection but not profiled yet). Surprisingly, these similar-looking cousins are not its closest relatives.

Instead, according to molecular studies by Butterworth and Wallace (2002), Mammillaria carmenae is most closely related to M pectinifera, a bizarre subminiature which is about to bloom in my yard. I hope to profile it soon. You’d never guess these two are so closely related. M pectinifera (means “comb-bearing”) resembles a strange, round top with spine-beds (areoles) like tiny, multilegged creatures. You’ll see!

See Also

ANDERSON, E. F. 2001. The cactus family. Timber Press, Portland, Oregon, USA.

HUNT, D. 1999. CITES Cactaceae checklist. Royal Botanic Gardens, Kew, Richmond, UK.

BUTTERWORTH, C.;  WALLACE, R.  2002. “Phylogenetic studies of Mammillaria (Cactaceae)—Insights from chloroplast sequence variation and hyptothesis testing using the parametric bootstrap”. American Journal of Botany 91(7): 1086–1098. 2004.

PILBEAM, J. 1999. Mammillaria. Nuffield Press, Oxford, UK.

Also… coming soon, Mr Sentient Meat, chief plant profiler for Succulent Sunday, is very excited to be upgrading his library with the top, current, go-to reference for cactus:

HUNT, D. 2006. New cactus lexicon. dh books. Sherborne, England, UK.

[I can practically feel your excitement from here. —Mr S M]

In game of natural selection, some cactus species have adapted so successfully that their natural habitat can extend across many hundreds of miles—several USA or Mexico states. Now in darkest winter, it’s time to talk about the “Snowball Cactus” which is just such a one: Mammillaria candida (Scheidweiler 1838). The spine covering on Mammillaria candida is so dense that the cactus does appear like a big snowball or puffball. The flowers can be light pink, dark pink, white with dark midveins… or even yellow!

Its habitat stretches across several states in northeastern Mexico: Coahuila, Nuevo León, San Luis Potosí, and Tamaulipas.

Mammillaria candida grown and photographed by Sentient Meat

Unlike some puffball-like mammillaria, Mammillaria candida has spines which really mean business. I thought it looked soft and friendly so I started to repot it without gloves. I thought if I moved slowly and gently I could just turn it upside down with one hand and rest it ever-so-lightly in my other hand. Big mistake! After trying this maneuver gingerly a couple times, I gave up. I can try again in the spring. With gloves.

Mammillaria candida (syn M. ortizrubiona) ML 656 - Photo : Michel Lacoste at Mammillarias.net

M candida is sometimes separated from the rest of Mammillaria into its own genus, Mammilloydia, because its seeds are not pitted and lack the perisperm found in all other mammillaria. Recent molecular studies, however, place M. candida squarely within Mammillaria, a huge genus which includes many cacti much more distantly related than Mammillaria candida.

Mammillaria candida - Photo : Willy at Mammillarias.net

See Also

Mammillarias.net gallery of species starting with C