Mammillaria elongata grow in size up to 6 inches tall and 12 inches wide. The coloration of these cacti is fascinating; they can range from bright yellow to reddish pink to almost white. However, the flowers on the Mammillaria elongata are mostly a bright yellow color, but there are also some pink and white varieties. Its flowers are white or yellow and bloom in the spring on densely packed clusters of elongated oblong stalks coated with innocuous (but sharp) brown or yellow spines.