Small globular to 8″ topped with a large cephalium with pale red bristles.
Soil
Melocactus zehntneri
Highly variable, mostly green. Round 10″ across to 20″ tall. Large cephalium when mature with small pale pink flowers. 10 to 20 ribs.
Mestoklema arboriforme
Large bonsai plants with highly variable exposed rootstock, branches will reach 2 to 3 feet tall. Small flowers at the new growth on branch ends only. Small cylindrical leaves.
Mestoklema tuberosum
Caudiciform mesemb to 30″. Semi-deciduous, branches can be cut back to the caudex as it grows.
Mimosa pudica
Tropical herb to 5ft.; lightly spiny stems, leaves close to touch. Keep moist, grows well as a houseplant.
Mirabilis jalapa
Stunning vibrant pink flowers. Grows a small caudex, bushy stems and green leaves, to 3ft tall.
May have been cultivated by the Aztecs for medicinal purposes.
Momordica rostrata
Cucurbit caudiciform vine with small orange-yellow flowers. Caudex to 12″, can vine 10 to 20 feet.
Monadenium coccineum
Euphorbia neococcinea
Thick green stems, bright red flowers. Will develop a 6″ caudex, vining stems can reach over 3ft. Broad leaves in shadier conditions.
Monadenium echinulatum
Euphorbia echinulata
Classic hooded Monadenium flowers. Deciduous. Keep dry when dormant. Will form a small knobby caudex eventually.
Monadenium ellenbeckii
Euphorbia bisellenbeckii
Shrub to 3’h. with several tender vertical stems, small leaves.
Monadenium invenustum
Euphorbia invenusta
Small caudex, 3ft. stems. Green-veined leaflets surround yellow inflorescence
Monadenium magnificum
Euphorbia magnifica
Thick green stems, large succulent green leaves, all topped with bright red inflorescence. Leaves come and go. Will form small caudex over time. Very low water.
Monadenium ritchei
Euphorbia ritchei
Stems to 16″, small leaves at tips, tiny pink blooms. Dry in winter
Monadenium rubellum
Euphorbia neorubella
Small caudex, 12″ striped stems; Pink flowers. Can be grown from stem cuttings
Monadenium stapelioides
Euphorbia succulenta
Euphorbia neostapelioides
Stems vertical to 12″; scoop-shaped leaves; tiny pink blooms
Monanthes anagensis
Low and shrubby, in the Crassula Family (Crassulaceae). Thick elliptical leaves. Erect stems to 6″.
Monanthes subcrassicaulis
Mediterranean climate succulent groundcover with small yellow flowers. Tight clumps, rounded leaves, grows in rocky crevices.
Monilaria moniliformis
Likes very rocky soils. Winter-growing, flowers in the spring. Will grow an irregular caudex topped with small paired tubular jeweled leaves when active, deciduous when dormant.
Monolena primuliflora
Large-leafed rare tropical epiphyte. Grown as a Houseplant can handle a variety of indoor light conditions, bright indirect is best. Fast draining soil, moderate water, high humidity. Occasionally mist the leaves. Will form a caudex, very slow growing. Red begonia-like flowers.
Myrmecodia beccarii
Epiphyte; hollow chambers in caudex colonized by ants
Myrtillocactus “Fukurokuryuzinboku”
M. geometrizans “Fukurokuryuzinboku”
Monstrose form with prominent tubercules, slow growing.
Myrtillocactus geometrizans
Well-branched, tree-like to 12ft.; clustered sparkly white flowers, edible berries.
Myrtillocactus geometrizans “Elite Crest”
Stunning, slow-growing, densely crested cactus. Bluish in full sun. Tends not to bloom or set fruit as much as the non-crested species.
Myrtillocactus geometrizans “Elite Monstrose”
New form from the M. “Elite Crest”, has lost the crest but is now a fa. monstrose. This form seems to be stable as a monstrose, and will not crest or revert to species. Blue in full sun.
Myrtillocactus geometrizans fa. cristata
Myrtillocactus “Crest”
Stunning, slow-growing, densely crested cactus. A number of different clones have more or less dense crests. Bluish in full sun. Tends not to bloom or set fruit as much as the non-crested species.