TABLE 1 in Mammillaria monochrysacantha (Cactaceae), a new endemic species from Guanajuato, Mexico

TABLE 1. Morphological comparison among species of Mammillaria with hair-like radial spines in Guanajuato, Querétaro, and San Luis Potosí.
Mammillaria bocasanaMammillaria crinitaMammillaria monochrysacanthaMammillaria scheinvarianaMammillaria schwarziiStem length × diameter (cm)6 × 3–52.5 × 3.54 × 52–4 × 63.8 × 3.2Number of radial spines25–3016–2628–3220–2435–40Number of central spines1–42–410–(1)5–9Radial spine vestitureGlabrousPubescentGlabrousGlabrousGlabrousFlower length × diameter (mm)15–22 × 15–2015 × 1514–15 × 9–1217–18 × 1015 × 12Tepals colorWhite to pale pink inner and outer tepals with brown middle stripeWhite to pale yellow inner and outer tepals with brown middle stripePale yellow inner and outer tepals with pale brown middle stripeWhite inner and outer tepals with pale pink middle stripeWhite inner and outer tepals with pale brown middle stripeArilloidPresentPresentAbsentAbsentAbsentDistributionSan Luis PotosíHidalgo, Querétaro, and GuanajuatoGuanajuatoQuerétaroGuanajuatoHabitatXerophytic scrub, 1750–2300 m elev., on humus and floors of igneous rocksXerophytic scrub to oak forest, 1900–2200 m elev., on floors of igneous rocksTropical deciduous forest, 1300– 1400 m elev., on igneous cliffsTropical deciduous forest, 1500–1700 m elev., on igneous cliffsEcotone of xerophytic scrub and oak forest, 2250–2350 m elev., on igneous cliffs