Research & evidence | Cactus Codex

Research notebook · checked 8 September 2026Source review · 8 September 2026

How this reference is built

Recent research notes are used to locate sources, then the public record is checked before a finding is included here. A real DOI establishes that a publication exists; it does not establish that a summary interpreted it correctly.

Botanical profiles identify the taxonomic treatment used. Grower records are attributed to their author. Experiments name their study host. Care guidance distinguishes a reasonable horticultural practice from a tested outcome.

Evidence by plant group

What the selected evidence can—and cannot—support
Plant group	Topic	Evidence and limits
Trichocereus / Echinopsis	Taxonomy and names	Kew species records and the 2025 family analysis. Genus-wide research does not authenticate a named clone. de Vos et al. · Cactus phylogenomics (2025) ↗
Lophophora	Taxonomic treatment	Four accepted species in the Kew treatment; koehresii is included under diffusa. Population labels need their own evidence. Kew · Lophophora ↗
Leucostele	Terscheckii placement	Kew accepts Leucostele terscheckii; older Echinopsis and Trichocereus names remain useful search terms. Kew · Leucostele terscheckii ↗
Opuntia	Cactus scale	Temperature-dependent development was studied on O. stricta. Do not turn this into a heat-treatment recommendation. Albuquerque Junior et al. · Cactus scale on Opuntia stricta (2023) ↗
Selenicereus / Hylocereus	Dragon-fruit canker	A matched host–pathogen experiment supports N. dimidiatum canker in red-fleshed dragon fruit. It does not diagnose Trichocereus spots. Mohd et al. · Dragon-fruit stem canker (2013) ↗
Gymnocalycium	Graft-associated soft rot	P. brasiliense was identified and pathogenicity tested on grafted G. mihanovichii. No universal calcium cure follows. Park et al. · Pectobacterium on grafted Gymnocalycium (2022) ↗
Parodia / Notocactus	Mixed virus infection	Six viruses were detected in one N. leninghausii f. cristatus. Possibility is demonstrated; prevalence is not. Park et al. · Six viruses detected in one cactus (2018) ↗
Schlumbergera	Several possible pathogens	UC IPM lists fungal, oomycete and viral problems on Christmas cactus. It is not a desert-cactus diagnosis key. UC IPM · Host–pathogen index ↗
Ariocarpus	Seed retention	A. kotschoubeyanus retained seeds with age-dependent germination behavior. Do not assign that response to every species. Plant Species Biology · Seed retention in Ariocarpus kotschoubeyanus (2022) ↗
Sedum · not a cactus	Root-mealybug trial	A useful succulent-host study, with an explicit transfer limit when discussing cacti. Gill & Kunkel · Root mealybug management on Sedum (2021) ↗
Pereskiopsis / Myrtillocactus	Horticultural rootstock choices	The Codex describes their use without universal speed multipliers, lifespan promises or an evidence-free ranking. Shimomura & Fuzihara · Vascular connection in cactus grafts (1977) ↗
Astrophytum, Aztekium, Echinocactus, Ferocactus, Mammillaria and other mentioned genera	Scope boundary	General growing and sourcing references apply as starting points. No newly imported genus-specific cure or frost threshold is claimed here. RHS · Growing cacti and succulents ↗

What changed in this edition

Taxonomic synonyms are separated from clone identity. Lophophora species counts now follow one explicit, dated treatment.
Shared BK and JS source numbers are no longer treated as universal clone aliases.
The pest guide includes root inspections, life-stage considerations, phytotoxicity testing and limits on transferring trials between hosts.
The health guide separates physiological injury, fungi, bacteria, oomycetes and viruses.
Fixed frost thresholds, universal fertilizer calendars and untested growth multipliers have been removed from advice.
Graft alignment allows vascular overlap with unequal diameters and an offset position.
The conservation guide corrects blanket claims about cultivated-plant and hybrid exemptions.

What remains open

The full community name registry contains many entries whose original source or clone chain has not been authenticated for this publication. Historical origin stories, unresolved aliases and metadata-only treatment leads are not promoted into facts here.

Some scientific literature is available only as a title or abstract. This edition does not claim to have verified every archived post, every registry identity or every paper in full. A missing search result is recorded as a search limitation, not proof that research or a specimen does not exist.