See Detective Derek 06/06: for discussion.
Some bromeliad species such as Neoregelia ampullacea show considerable variation. Over 40 distinct forms are known in cultivation. By current botanical classification, none is different enough to warrant variety status but many have cultivar names. Culture and climate affect their appearance but, under fairly uniform growing conditions, the subtle differences become apparent amongst the following loosely grouped plants.
“Tigrina types.” The true Neoregelia tigrina has relatively narrow stripes, pure white flowers, and stolons of up to 25 cm in length. It is unlike any known N. ampullacea. At least 20 different kinds of "tigrina types" are cultivated, ranging from tiny tubes 2 cm tall by 1 cm in diameter to a large form 20-25 cm tall with 10cm stolons. Characteristic are the mid-brown to reddish crossbands on the reverse of the leaves and less regular banding on the 5-8 green, upper leaf blades. Often the cross banding is intermingled profusely with speckles or minute spots, particularly on the obverse. Foliage base colour varies too from scurfed, mossy grey-green to bright lettuce green. In this category, the lower half of the tight rosette is comparatively narrow, flaring more at the top, usually with cusped or rounded leaf tips.
The "variegata" form with yellowish green leaf margins is a tigrina type along with 'Freckles', 'Midget', 'Zebrina' (upright 15 cm tube with wide, maroon stripes). Others in this group are:
. 'Pixie', a N. ampullacea cultivar similar to 'Zebrina' has strong, purplish red zebra-like crossbands and pointed leaf tips.
. 'Purpurea', heavily striped burgundy at the rosette base and reverse.
. 'Black Beauty', an intraspecific cross of N. ampullacea x N. 'Tigrina', with the entire foliage liberally splotched and banded sepia red when grown in bright light.
"Punctatissima types." Again, a misleading term because the true Neoregelia punctatissima has white, sericeous, transverse spots, pure white flowers, and a species "known with certainty from the type collection alone, doubtfully in cultivation." Prominent characteristics of about a dozen different variants are a fuller, more open rosette 10-20 cm across with 8-15 lustrous leaves appearing greenish yellow in strong light, even bright gold in the tropics, and a series of punctuated brown or red crossbands that are more pronounced in the reverse. The actual width, spacing, and number of these hieroglyphs distinguishes one from another. The "Rubra" form has coppery bronze foliage with darker, brick red markings.
Amongst both "tigrina" and "punctatissima types" petal colour ranges from pale lavender to deepest violet on the blade margins, the central portion being whitish.
Within the species Neoregelia ampullacea there is 'Purple', a plain green, compact, full rosette with a rosy, purple-flushed centre. N. lilliputiana is a closely allied dwarf of the genus at 2-3 cm in height and 1 cm across. It may not be botanically distinct from N. ampullacea.
Other Neoregelia ampullacea cultivars include 'Empressa', 'Grand Duchess', 'Marie?', 'Minnie Mouse', 'Nitritis', 'Princess', 'Regalia', 'Speckles', and 'Spreckle'. These miniatures are invariably hardy, attractive, and prolific. Often filling a pot, bowl, mobile, or hanging basket in a few seasons. Their climbing or cascading growth habit is an arresting sight when allowed to ball or mass into 100-tube colonies. Many N. ampullacea hybrids abound often retaining that robustness and strikingly barred foliage. They are ideal for collectors with limited space.