Bromelioideae

Approximately the same array of fauna pollinate Bromelioideae as pollinate Pitcairnioideae and Tillandsioideae. Likewise, ornithophily probably predominates, according to reports and oral syndromes displayed among the larger genera (e.g., Aechmea, Billbergia, Neoregelia, Quesnelia; Table 6.1). Flexibility, like that documented by visits by hummingbirds and butter ies (Eurema diara and Phoebus spp.) to Costa Rican Bromelia pinguin and B. karatas (Hallwachs 1983), may be especially common in this subfamily. Unusual morphology complicates some interpretations, for example the nearly submerged, capitulate in orescence of most Neoregelia species (Fig. 3.2A). Flowers equipped with lavender to pink or white corollas barely extend above the surface as if to deter predators seeking buds and developing fruits (Fig. 3.5B). Nevertheless, insects and hummingbirds readily access nectar located deep within the tubular corollas.

Members of the Neoregelia/Nidularium complex and the other nidulate

Bromelioideae usually exhibit one of two ornamentations, which in one and perhaps both instances attract fauna (Fig. 2.13F; Leme 1997,1998a,b). Immature foliage and the lower parts of older leaves often accumulate bright red through orange to purple pigments (occasionally albinistic as in certain Navia species, e.g., Navia ocellata (formerly N. lactea)) following oral induction, and sometimes these displays persist long enough to in u-ence seed dispersal. Rather than conspicuously pigmented centers, other Neoregelia and a few Hohenbergia and Nidularium species and Wittrockia superba feature red to purple leaf tips, although not necessarily for the same purposes (Fig. 2.13F; Chapter 11). Parallels exist in Tillandsioideae (e.g., Vriesea platynema, V. minuta). Guzmania sanguinea much more closely resembles the rst group in the way its owers extend just above the surface of the phytotelmata maintained by utriculate foliage.

Sweet fragrances emanating from small owers on often dull in ores-cences signal entomophily in exceptional Aechmea (e.g., Aechmeapurpure-orosea, A. lingulata), the largest (>150 species) and among the most arti cial of the bromelioid genera. Corollas of Aechmea fasciata change color from powder blue early in the day to deep rose-red by late afternoon whether pollinated or not (Fig. 3.2G). Most Billbergia produce pendant, rapidly elongating in orescences bearing large, ephemeral pastel primary bracts and hummingbird-serviced owers (Fig. 3.2F); exceptional ento-mophilous types (e.g., fragrant B. horrida) stand upright and present owers subtended by vestigial, equally pale bracts. Billbergia robert-readii departs farthest from the norm with its odd-smelling, night-blooming, upturned grayish chiropterophilous owers born on a lax spike. Reproductive organs generally suggest that fewer Bromelioideae than Pitcairnioideae or Tillandsioideae depend on bats to produce seeds.

Ant-inhabited Aechmea bracteata ripens full crops of purple-black berries on densely owered panicles in the greenhouse following displays of small yellow owers that probably attract insects in situ (Fig. 3.2C). Its deep pink in orescence bracts seem to advertise fruits rather than oral nectar. Unlike the similarly pigmented appendages born by many Billbergia that sometimes begin to fade even before the last ower opens, those of Aechmea bracteata remain turgid and bright, withering only after the comparatively inconspicuous berries begin to shrivel.

Characteristics of owers, in orescences and foliage further indicate that insects pollinate most members of several of the larger, predominantly terrestrial genera and also the large majority of Hohenbergia species. Cryptanthus, which deviate from other Bromelioideae by chromosome numbers and gender expression (subgenus Cryptanthus; Chapter 11), all qualify. Andromonoecy (staminate and perfect owers on the same plant) prevails except for members of exclusively perfect- owered subgenus Hoplocryptanthus. Corollas range from white to pink, and the exceptional species (e.g., C. exaltatus, C. odoratissimus in Hoplocryptanthus) emit powerful, spicy perfumes. Closely related Orthophytum includes populations with conspicuous red bracts (e.g., O. saxicola), while more of its membership exhibit entomophily (e.g., O. humile).

Short, globose, axillary in orescences obscured by dense foliage mark Greigia species as candidates for some of the more unusual pollination and seed dispersal syndromes among Bromeliaceae (Fig. 3.2E). Flowers range from drab (e.g., Mexican G. oaxacana) and obscured by subtending, folia-ceous bracts and adjacent foliage to quite colorful (e.g., Chilean G. sphacel-ata) due to red to pink corollas and bracts. Some members of similarly overlooked Fascicularia, Fernseea and Ochagavia display showy, bird-attracting in orescences.

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