Argentina: Images of Dry Tropical Habitat

All of these photographs were taken in extreme northern Argentina in an area broadly known as the Chaco. Click on a thumbnail for a larger image:

Plants

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1. Large terrestrial bromeliad (Bromeliaceae) Aechmaea distacantha. Like many bromeliads, A. distacantha catches water in a cup formed by its leaves. The water in the cup is used by the plant but is also a valuable resource to many small animals. 2. Inflorescence of another large terrestrial bromeliad in the genus Bromelia. The leaves of the rosette that are closest to the inflorescence are red in this photograph. Many bromeliads produce red or other colored leaves or bracts when they flower. 3. Pimply seed pod of the liana Pithecoctenium in the Bignoniaceae. 4. The seeds of Pithecoctenium are fringed with a diaphanous wing.
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5. Bright yellow flowers of the carnivorous plant Utricularia (Lentibulariaceae) growing in a seasonally moist area. 6. - 8. As in many parts of the world, grasses are important components of Chaco vegetation. Common members include: 6. Chloris sp.; 7. Paspalum sp.; 8. Schizachyrium microstachys.
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9. Ferns in the genus Pellaea (?) are commonly found in dry areas. 10. , 11., 12., 13., 14. Silk Floss Trees (Chorisia spp.in the Bombacaceae) are some of the most conspicuous members of Chaco vegetation. Some of them are massive bottle trees and all of them have large, colorful flowers. 11. and 12. show the habit and spiky trunk of C. speciosa, while 13. and 14. show the bud and flower. 14. is a flower of C. insignis in the process of opening.
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1. Spider in web in the center of an A. distacantha cup.
2. This is one of the weirdest things I've ever seen. It's a giant spider web spun cooperatively by 30 or so colonial spiders. There are a few big strands that are thick enough to trip over that anchor the web. These strands remain in place all the time. In the evening, the spiders come out and get to work spinning a series of smaller webs anchored by the big strands. It' s almost creepy to see them working quickly and silently, but perfectly coordinated, even optimizing the web to suit whatever prey animal might be most abundant that night. In the morning, they take the whole thing down again.
3. Head of the large toad Bufo marinus.
4. Eye and face of a pacú fish.