Mabea parguazae Jabl. Isotype
Macleania subsessilis Luteyn Isotype
Macromeria pringlei Greenman Isotype
Madia filipes var. macrocephala Isotype
Maesa procera B. C. Stone Isotype
Malacolepis coulteri (Harv. & Gray) Heller Isotype
Mallinoa corymbosa Coulter Isotype
Malvastrum greenmanianum Rose Isotype
Malvaviscus pringlei E. G. Baker Isotype
Mammillaria furfuracea Watson Isotype
Mandevilla sertuligera Woodson Isotype
Manfreda pringlei Rose Isotype
Manihot carthaginensis Muell.
Manihot caudata Greenman Isosyntype
Manihot intermedia Weatherby Isotype
Margaranthus sulphereus Fernald Isosyntype
Marilaunidium tenue Small Isosyntype
Marsdenia pringlei Watson Isotype
Marsdenia trivirgulata
Marsilea mollis Robinson & Fernald Isotype
Marsilea mollis Robinson & Fernald Isotype
Mascagnia macroptera var. flabellariicarpa Niedenzu Isotype
Mascagnia macroptera var. jussieuana Niedenzu Isolectotype
Matelea decumbens W. D. Stevens Isotype
Matelea decumbens W. D. Stevens Holotype
Matelea macvaughiana W. D. Stevens Holotype
Matelea sepicola W. D. Stevens Holotype
Maxillaria seymouriana Atwood Isotype
Mecranium latifolium (Cogniaux) Skean Isotype
Medinilla amplectens J. C. Regalado Holotype
Medinilla beamanii J. C. Regalado Holotype
Meibomia pinetorum Rose & Painter Isotype
Melampodium bibracteatum Watson Isotype
Melica alba Hitchcock Isotype
Melica harfordii var. minor Vasey Isotype
Melica montezumae Piper Isotype
Melica multinervosa Vasey Isotype
Memecylon elmeri Merr. Isotype
Menispermum mexicanun Rose Isotype
Menodora helianthemoides var. parviflora Greenman Isotype
Mentzelia involucrata S. Watson Unknown
Mentzelia multiflora var. integra M. E. Jones Isosyntype
Mentzelia parviflora Heller Isotype
Mertensia cusickii Piper Isotype
Mertensia umbratilis Greenman Isosyntype
Metasequoia glyptostroboides Hu & Cheng Isotype
Metastelma macropoda Greenman Isotype
Miconia pailasana Wurdack Isotype
Microsechium gonzalo-palomae Lira Isotype
Microstylis streptopetala Robinson & Greenman Isotype
Microstylis tenuis Watson Isotype
Mimophytum omphalodoides Greenman Isotype
Mimosa affinis B.L. Robinson Unknown
Mimosa buceragenia Robinson Isotype
Mimosa caerulea Rose Unknown
Mimosa calcicola Robinson Isotype
Mimosa ionema Rose Isotype
Mimosa lacerata Rose Isosyntype
Mimosa polyanthoides Robinson Isotype
Mimosa stipitata B. L. Robinson Isotype
Mimulus ampliatus Grant Isotype
Mimulus clivicola Greenman Isosyntype
Mimulus deflexus Watson Isotype
Mimulus jungermannioides Suksdorf Isotype
Mimulus micranthus Heller Isotype
Mimulus serotinus Suksdorf Isotype
Minkelersia multiflora Rose Isosyntype
Mirabilis pringlei Weatherby Isotype
Mirasolia diversifolia Hemsley Isosyntype
Monardella pallida A. Heller Isotype
Monardella pinetorum A. Heller Isotype
Monochaetum pringlei Rose Isotype
Montanoa anomala Robinson & Greenman Isotype
Montanoa hemsleyana (Kuntze) Blake Isotype
Montanoa macrolepis Robins. & Greenm. Isotype
Montanoa palmerii Fern. Isotype
Montanoa tehuacana Robins. Isotype
Morongia latidens Small Isotype
Mortonia diffusa Rose & Standley Isotype
Muhlenbergia arizonica Scribner Isosyntype
Muhlenbergia biloba Hitchcock Isotype
Muhlenbergia brevifolia Scribner ex Beal Holotype
Muhlenbergia densiflora Scribner Isotype
Muhlenbergia depauperata Scribner Isolectotype
Muhlenbergia dumosa var. minor Scribner ex Beal Holotype
Muhlenbergia elata Vasey Isotype
Muhlenbergia elata Vasey Isotype
Muhlenbergia elongata Scribner ex Beal Syntype
Muhlenbergia enervis (Scribner) Hitchc. Unknown
Muhlenbergia firma Beal Holotype
Muhlenbergia flavida var. strictior Scribn. ex Beal Unknown
Muhlenbergia flavida Vasey Isotype
Muhlenbergia gracilis var. enervis Scribner ex Beal Holotype
Muhlenbergia longifolia Vasey Isotype
Muhlenbergia longiglumis Vasey Isosyntype
Muhlenbergia longiglumis Vasey Isosyntype
Muhlenbergia nebulosa Scribner ex Beal Holotype
Muhlenbergia neomexicana Vasey Isotype
Muhlenbergia polycaulis Scribner Isotype
Muhlenbergia pringlei (Scribn.) Scribner Unknown
Muhlenbergia pulcherrima Scribner ex Beal Holotype
Muhlenbergia scoparia Vasey Isosyntype
Muhlenbergia strictior Beal Holotype
Muhlenbergia sylvatica var.
Muhlenbergia sylvatica var. pringlei Scribner Isotype
Museniopsis arguta Rose Isotype
Museniopsis biennis Coult. & Rose Isotype
Museniopsis tuberosa Coulter & Rose Isosyntype
Musineon alpinum Coult. & Rose Isotype
Myrica pringlei Greenman Isotype
Myriophyllum mexicanum Watson Isotype
Myrsine lanceolata (Wawra) Heller Isotype