Please help with ID of this plant

[David48]

Please might someone help with identifying of this plant. It was bought unnamed in a Brazilian market by a friend.

It reminded me of mammillaria magnimamma which I once owned years ago except it has almost no spines and the tubercles are smaller than my previous plant. The plant is columnar fast growing and very free flowering with red flowers which appear at the apex. In a few months the top third of this plant has flowered.

In various links I have seen a number of magnimamma varieties listed one was I think "toledo" which looked similar. However this plant flowers from the new growth so if mammillarias only flower from the second year growth this would appear to put it into another genera.

Please any ideas to give this wonderful grower and flowerer a name.

[Saguaro123]

Looks like Mammillaria polythele f. inermis

http://www.cactus-art.biz/schede/MAMMIL ... nermis.htm

[David48]

Thank you. Yes it looks a very good match. But what puzzles me now is that a feature of mammillarias is that they flower from the previous year´s growth (or so I believe) and this is flowering from its new growth. Have I misunderstood this or is it a rule only loosely applied?

[george76904]

You are correct in that most mammillarias flower from "old growth". You are also correct in that it is a unique feature of the genus. In fact I believe that was the reason that Coryphantha was split from mammillaria. However there are some instances where the plants flowered from the "new growth" but were still left in mammillaria for whatever reason the taxonomists chose.
Taken from the article Saguaro123 linked "A rare peculiarity of this plant is that the flowers are produced either from the axil and from the apex of the tubercles too."

[David48]

Thank you. Puzzling and intriguing.

[iann]

This plant is monstrose. The normal growth patterns are disrupted leading to features like missing spines and flowers on new growth.

[David48]

I think Mammillaria polythele is the correct ID therefore it is not a one off but representative of a large population of plants.

Its location nearly on the equator could mean it might flower and grow without stop all year round. I am looking forward to finding out.

[iann]

Here, they don't get around to flowering until well into summer. Then they are reluctant to give up until it really gets cold and dark.

[David48]

Here there´s 365 days of summer, 85-95F, day and night. But it always gets dark around 17:30.

One interesting thing is half the year the sun shines from the north and half the year it shines from the south so a plant could be in full sun 6 months then shade the other 6 months (although the sun is very high in the sky as it tracks through the day)