Mammillaria karwinskiana (Syn. Mammillaria nejapensis)-Silver Arrows

Mammillaria karwinskiana (Silver Arrows) after I brought it home on 9-21-18, #510-7.

Silver Arrows

Mammillaria karwinskiana

mam-mil-AR-ee-uh  kar-winz-kee-AH-na


Mammillaria nejapensis

Synonyms of Mammillaria karwinskiana (45): Cactus fischeri (Pfeiff.) Kuntze, Cactus geminatus (Scheidw.) Kuntze, Cactus karwinskianus (Mart.) Kuntze, Cactus pyrrhocephalus (Scheidw.) Kuntze, Cactus subpolyedrus Kuntze, Cactus virens (Scheidw.) Kuntze, Mammillaria beiselii Diers, Mammillaria closiana Roum., Mammillaria confusa (Britton & Rose) Orcutt, Mammillaria confusa var. centrispina R.T.Craig, Mammillaria confusa var. conzattii (Britton & Rose) R.T.Craig, Mammillaria confusa var. robustispina R.T.Craig, Mammillaria conzattii (Britton & Rose) Orcutt, Mammillaria fischeri Pfeiff., Mammillaria geminata Scheidw., Mammillaria jalappensis Pfeiff., Mammillaria jozef-bergeri Wojn. & Prajer, Mammillaria karwinskiana subsp. beiselii (Diers) D.R.Hunt, Mammillaria karwinskiana var. flavescens Zucc. ex Pfeiff., Mammillaria karwinskiana subsp. nejapensis (R.T.Craig & E.Y.Dawson) D.R.Hunt, Mammillaria karwinskiana var. virens (Scheidw.) Salm-Dyck, Mammillaria karwinskii Lawr., Mammillaria malletiana Cels, Mammillaria malletiana var. pyrrhocephala (Scheidw.) Schelle, Mammillaria multiseta C.Ehrenb., Mammillaria nagliana Repp., Mammillaria nejapensis R.T.Craig & E.Y.Dawson, Mammillaria nejapensis var. brevispina R.T.Craig & E.Y.Dawson, Mammillaria nejapensis var. longispina R.T.Craig & E.Y.Dawson, Mammillaria neomystax Backeb., Mammillaria parmentieri Link & Otto, Mammillaria polygona Zucc. ex Pfeiff., Mammillaria pyrrhocephala Scheidw., Mammillaria pyrrhocephala var. confusa (Britton & Rose) Borg, Mammillaria pyrrhocephala var. donkelaerii Salm-Dyck, Mammillaria pyrrhocephala var. malletiana (Cels) Borg, Mammillaria strobilina Tiegel, Mammillaria subpolyedra Salm-Dyck, Mammillaria tropica Repp., Mammillaria virens Scheidw., Neomammillaria confusa Britton & Rose, Neomammillaria conzattii Britton & Rose, Neomammillaria karwinskiana (Mart.) Britton & Rose, Neomammillaria pyrrhocephala (Scheidw.) Britton & Rose, Neomammillaria subpolyedra (Salm-Dyck) Britton & Rose

The label says this plant is a Mammillaria nejapensis but, according to Plants of the World Online by Kew, Mammillaria nejapensis is a synonym of Mammillaria karwinskiana.

Mammillaria karwinskiana Mart. is now the correct and accepted name for this species. It was named and described by Carl (Karl) Friedrich Philipp von Martius in Nova Acta Physico-Medica… in 1832.

The synonym, Mammillaria nejapensis R.T.Craig & E.Y.Dawson, was named and described by Robert T. Craig and Elmer Yale Dawson in Allan Hancock Foundation: Occasional Papers in 1848.


Mammillaria karwinskiana on 9-21-18, #510-8.

I bought this plant from Lowe’s on clearance on September 21, 2018. The label says:

“Native to Oaxaca, Mexico, forms globular stems with silvery white spines, dense wool at the areoles. Becomes slightly columnar, branching to form large clusters. Flowers are pale yellow with reddish midstripe. Water thoroughly when soil is dry.”

The plant is growing in a 4 oz. (2 1/2” diameter x 2 1/4” tall) pot. The plant measures approximately 1 7/8” tall x 2 3/16” wide without the spines.


Mammillaria karwinskiana from the top on 9-21-18, #510-9.

Family: Cactaceae
Origin: Central and Southwest Mexico and Guatemala
Zones: USDA Zones 9b-11 (25-40° F)
Size: Hmmm… Maybe up to 8” or so tall.
Light: Sun to light shade. If grown inside over the winter, you should gradually increase the amount of light gradually when you put them outside.
Soil: Very well-draining soil. Potting soil amended with grit and price or perlite.
Water: Average during the summer and very seldom during the winter. Allow to dry out between watering

Mammillaria karwinskiana is one of only a few Mammillaria species commonly referred to as “Owl Eye Cactus” known for their dichotomous branching. I think this means the plant (stem) divides into two parts. Then the two become 4 and so on… I haven’t experienced this yet, be but could get interesting.


Mammillaria karwinskiana on 10-10-18, #519-47.

I moved the potted plants inside for the winter on October 10 because the weather forecast said we would be having an “F” in a few days and the evening temperatures were going to be dropping. I always measure the cactus and some of the succulents when I move them inside to see how much they have grown in the past year. I didn’t measure this plant then because I only had it for a short time and it hadn’t grown.


Mammillaria karwinskiana on 11-29-18, #534-19.

November 29 was a nice spring-like day, so I took the cactus to the back porch for a photo shoot. I was working on a post to show the difference between the cactus in my collection.


Mammillaria karwiskiana close-up on 12-1-18, #535-15.

Mammillaria karwinskiana differs from the four subspecies (which aren’t accepted names at the moment) because it lacks a central spine. Even though the photo looks like there are five radial spines there are actually six (I counted to make sure). The description of this plant on Llifle taught me a lot of new words… I looked up the words on the CactiGuide Glossary of Cacti Terms then looked at the plant to figure out what it was talking about. 🙂 Then I realized I have been spelling the website name wrong for FIVE years.

Anyway… It says, “The Axil is very woolly, with tufts of white hair and long white bristles.” This is talking about the top of the plant. I think the “bristles”, which are stiffened hair (according to CactiGuide), become the radial spines. Not sure, though, because I didn’t notice any long white bristles on this plant. Maybe with age… It also says the tubercles are, “Firm, pyramidal, arranged spirally with 13-21 parastichys.” Hmmm… According to the glossary of terms, a parastichy is a secondary spiral in phyllotaxis. GEEZ! What is a phyllotaxis? It says, “Phyllotaxis is a mode of arrangement of leaves in relation to axis.” WHAT? LEAVES?!?! WHAT LEAVES? The tufts of hair between the tubercles are interesting, though, as is the wool on the tips of the nipples. WHOOPS! I mean tubercles…


Mammillaria karwinskiana (Silver Arrows) on 6-22-19, #593-29.

The potted plants are enjoying being outside for the summer. Most of the cactus are on the back porch in full sun.

I was fairly busy during the summer so I wasn’t able to take a lot of photos. The cactus all did very well despite a little neglect.


Mammillaria karwinskiana (Silver Arrows) at 3 1/4″ tall x 2 3/4″ wide on 10-11-19, #639-61.

I had to move the potted plants inside for the winter on October 11 because an “F” was in the forecast. I always take photos of the plants when I bring them inside and measure the cactus and some of the succulents. The Mammillaria karwinskiana measured 3 1/4″ tall x 2 3/4″ wide. It was only 1 7/8″ tall when brought it home on 9-21-18 so it has grown a lot.


Mammillaria karwinskiana (Silver Arrows) from the top on 10-11-19, #639-63.

The Mammillaria karwinskiana is fairly wooly, but not as much as the Mammillaria hahniana. I could not remember if there were buds when I brought the cactus inside or not. Kind of hard to tell what is under the wool. The top of cactus always looks neat. For sure, the wool on this cactus has gotten A LOT thicker. Maybe it is growing more for the winter.


Mammillaria karwinskiana (Silver Arrows) on 11-11-19, #648-4.

The flowers were beginning to open when I took this photo on November 11. It is always interesting how the buds form and open facing the inside of the house first instead of the sunny side.


Mammillaria karwinskiana (Silver Arrows) on 11-11-19, #648-5.

I am really glad the flowers aren’t pink like several other Mammillaria in my collection. Information on Llifle says the flowers of this species are creamy-white to yellow with maroon midveins.


Mammillaria karwinskiana (Silver Arrows) flowers on 11-18-19, #653-1.



Mammillaria karwinskiana (Silver Arrows) flowers on 11-18-19, #653-2.



Mammillaria karwinskiana (Silver Arrows) on 11-18-19, #653-3.

There are more buds almost all the way around the plant.


Mammillaria karwinskiana (Silver Arrows) on 11-23-19, #655-4.

I took this photo when the flowers were fully open and some of earlier ones are beginning to get a little droopy.


Mammillaria karwinskiana (Silver Arrows) on 11-14-19, #660-1.

There were eleven buds and flowers when I took the above photo on November 14. These buds are on the backside of the plant.

I will continue adding more photos and information as time goes by. This one will be interesting to watch and see how long it takes the stem to split. 🙂

You can read my Cactus Talk & Update and Cactus & Succulent Tips to get my opinion about growing cactus and succulents.

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