Miniaturization

Figure 2.1. Schematic diagram illustrating neoteny in Tillandsioideae whereby an ancestor with mesomorphic foliage organized to maintain a phytotelmata gave rise to descendants that lack phytotelm architecture and extensive root systems and instead exhibit overall miniaturization combined with either reduced or increased numbers of leafy nodes. All scale bars = 1 cm. See text for additional details.

electron microscopy (e.g., Benzing et al. 1978) and histochemistry (e.g., Owen et al. 1988). Tomlinson (1969) devoted a substantial portion of Volume 3 of the Anatomy of the Monocotyledons to the most recent review of this information. We gratefully acknowledge the importance to our treatment of Tomlinson s synthesis and the growing body of related, interpretative information being amassed by plant physiologists and ecologists.

Our primary concern here is those aspects of vegetative structure that distinguish Bromeliaceae among families (e.g., epiphytism) and foster importance in ecosystems. Featured species showcase adaptive morphology, and, for example, illustrate how shoot architecture in uences access to

Figure 2.2. Bromeliad architecture. (A) Dyckia sp. in vegetative state. (B) Dyckia sp. with lateral in orescence. (C) Hemiepiphytic Pitcairnia sp. illustrating heterophylly.

(D) Neoregelia abendrothae ramets with only juvenile or juvenile and adult foliage.

(E) Brocchinia acuminata, sun (compact) and shade (caulescent) forms. (F) Ronnbergia ecuadoriana illustrating putatively primitive architecture. (G) Cottendorfia florida with leaves cut short to expose thick, re-resistant stem. (H) Distichous Dyckia estevesii.

Figure 2.2. Bromeliad architecture. (A) Dyckia sp. in vegetative state. (B) Dyckia sp. with lateral in orescence. (C) Hemiepiphytic Pitcairnia sp. illustrating heterophylly.

(D) Neoregelia abendrothae ramets with only juvenile or juvenile and adult foliage.

(E) Brocchinia acuminata, sun (compact) and shade (caulescent) forms. (F) Ronnbergia ecuadoriana illustrating putatively primitive architecture. (G) Cottendorfia florida with leaves cut short to expose thick, re-resistant stem. (H) Distichous Dyckia estevesii.

Figure 2.3. Schematic diagram illustrating three patterns of growth in Bromeliaceae. (A) Sympodial branching with determinant ramets. (B) Monocarpy. (C) Monopodial with axillary owering.

resources that most plants obtain from soil. Finer details of carbon management, water balance and mineral nutrition are deferred to later chapters. Likewise, taxonomy receives scant attention in this chapter except where classi cation happens to parallel form (e.g., foliar trichomes) that also in uences plant performance. In the nal analysis, our subject is how what seems to be the fundamental monocot body plan, combined with often novel arrangements and modi cations of leaves, permits Bromeliaceae to occur in most of the life zones comprising the American tropics.

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