CactiGuide.com

Why not gymnocalycium? Some of the best plants in my experience and very reliable flowerers. Plants will stay small and some have very beautiful spination
Gymnocalycium baldianum: very fast from seed and can flower in 1.5 years while being less than inch in diameter. They flower from may through august for me. Some of my baldianum flowers: Some closeups: One of the tiny flowering plants a little over an inch. Smaller ones have buds too: Gymnocalycium damsii: a little slow growing but has beautiful stress colors. I mistakingly got the white flowering variety rather than the pink/purple. 2 inch specimen in 3 inch pot with 19 flower buds (so far). Not sure all will follow through: Gymnocalycium schickendantzii: amazing spination Gymnocalycium pflanzii: the spines will turn an amazing color when wet. For me they grow like a weed. Seedlings grew from 0.5cm (.2 inches) to 5-6cm (2+ inches) in one season. I have seen nothing grow as fast! This is their prime flowering time and photos will be added as they progress

Gymnocalycium hyptiacanthum
Gymnocalycium amerhauseri
Gymnocalycium stellatum
Gymnocalycium uruguayense v. rubriflorum

Schutziana is an online Journal for Gymnocalycium enthusiasts. Most are available to download in several different languages (note the flags indicating the language) also back numbers can be found on the column on the left. I think all are downloadable in English and contain probably the most up to date information on Gymnocalycium's available anywhere.

https://www.schuetziana.org/index.php/downloads

I usually download to a file for E-Books and Journals on my computer in order to save time keep downloading, but you can also transfer to CD or Memory stick to produce your own "plug-in library" when needed, particularly as so many journals are going online these days.

This one covers G. baldianum.

https://www.schuetziana.org/downloads/S ... 2017_3.pdf

This cacti of the month has come up just as I brought my first Gymnocalycium over the weekend so I'll be watching for interesting replies here!
This is a little G.castellanosii and I just love the spines.

It's one of those species where the spination can vary, but usually strong spined. See:-

http://www.llifle.com/Encyclopedia/CACT ... tellanosii

http://www.cactus-art.biz/schede/GYMNOC ... anosii.htm

Thanks for the links! I'd looked at the Llifle one already
What requirements are there to get a Gymnocalycium to flower? Does it have to be a certain age/size or given certain conditions? (I'm thinking more generally as a genus rather than just specific to the species I've got)

They like heat, they're tropical cacti. Many of them bloom when very young.

I love them, but I've had terrible luck with them. My first was a mihanovichii, with green-streaked yellow flowers - I got to see one before it got caught in a surprise thundershower while still wet after it had been watered, and it rotted. Bad luck+inexperience. Tried to start baldianum from seed, seed was no good. Bought a beautiful damsii with purple markings, produced pink flowers constantly whenever the weather was warm. Had it for a couple years. Last Spring it was eaten by slugs during an early heat wave - apparently the big slugs were still active, and desperately seeking moisture as everything dried up. Must have been a huge slug since it ate the entire core out of it in one night. Still contemplating my next victim...

greenknight wrote: ↑Mon May 07, 2018 9:52 pm Last Spring it was eaten by slugs during an early heat wave - apparently the big slugs were still active, and desperately seeking moisture as everything dried up.

Try sprinkling some wood ash around your pots. It is very effective in deterring slugs

ElieEstephane wrote: ↑Tue May 08, 2018 12:16 pm

greenknight wrote: ↑Mon May 07, 2018 9:52 pm Last Spring it was eaten by slugs during an early heat wave - apparently the big slugs were still active, and desperately seeking moisture as everything dried up.

Try sprinkling some wood ash around your pots. It is very effective in deterring slugs

I know how to deter slugs, I simply wasn't expecting slug problems in that kind of weather. Seems it hadn't been dry long enough to drive all the slugs into hiding, though.

I once collected Gymnocalycium with strong spines.
They have been reduced quite many but some of them have still been remained.
I sowed seeds in 2003.
It is not flowering season in here.

They are interesting little cacti. I've got a dozen that came in my mixed seed packet that I sowed a few years ago. Now about an inch or two wide I'm hoping to see them flower.

Pink baldianum flowers: Damsii flowers that are always very reluctant to open completely:

It worth having several if not many species of Gynocalycium in the collection.

Gymnocalycium saglionis is one of the largest in the genus reaching 30 cm and more height sometimes.

This is my plant, still young and growing.

A mature saglionis is one of the best species of the genus. Without flowers, people regularly confuse them with pflanzii