Figure 5 - uploaded by Mateusz Wrazidlo
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Vegetation on the top of the sandstone boulder location: 1) Bonnetia roraimae shrub vegetation with Stegolepis, with Mona-tepui visible in the background; 2) Sandstone boulders on the southwestern talus slope of Ptari-tepui, looking SE; 3) Shrub vegetation on the boulder, looking NW; 4) Heliamphora collina x purpurascens growing among shrubs on the top of the boulder.
Source publication
In May 2018 I had the opportunity to co-organize an independent expedition to the areas surrounding the massif of Ptari-tepui and Sororopan-tepui in Estado Bolívar, Venezuela. My group led by a team of Pemón guides from the community of Santa Teresita de Kavanayen succeeded in reaching the location of the first scientific expeditions to the massif...
Context in source publication
Context 1
... trail ended on the surface of one of the large sandstone boulders which were common in the slope areas. The summit of the boulder was partially bare rock, and in some parts thick shrub vegetation growing all around the slopes (Fig. 5), which directly matched the description of the location left by J. A. Steyermark on his Heliamphora heterodoxa type collections: "matted on mossy exposed top of big boulder; (…), Ptari-tepui, Bonnetia roraimae forest on southwest-facing shoulder, altitude 2000-2200 meters" (Steyermark 1951). Among the shrubs a significant amount of ...
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ملخّص
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Citations
... The wider angle, roughly the mean estimated in uncrowded conditions (Figure 6), leads to evenly spaced pitchers in the mature rosette ( Figure 7A, B). Mature rosettes typically comprise five active pitchers (e.g., Butschi et al., 1989;Wistuba et al., 2005;Wrazidlo, 2019;Golos, 2020), and we added a sixth pitcher to demonstrate how a new pitcher would overlap with an older inactive pitcher ( Figure 7B). Furthermore, we envisioned how a clonal cluster of rosettes emerging from the rhizomes of a single plant could fill a confined space, such as a depression in the rock substrate ( Figure 7C). ...
Premise
The evolution of carnivorous pitcher traps across multiple angiosperm lineages represents a classic example of morphological convergence. Nevertheless, no comparative study to‐date has examined pitcher evolution from a quantitative morphometric perspective.
Methods
In the present study, we used comparative morphometric approaches to quantify the shape space occupied by Heliamphora pitchers and to trace evolutionary trajectories through this space to examine patterns of divergence and convergence within the genus. We also investigated pitcher development, and, how the packing of pitchers is affected by crowding, a common condition in their natural environments.
Results
Our results showed that Heliamphora pitchers have diverged along three main axes in morphospace: (1) pitcher curvature; (2) nectar spoon elaboration; and (3) pitcher stoutness. Both curvature and stoutness are correlated with pitcher size, suggesting structural constraints in pitcher morphological evolution. Among the four traits (curvature, spoon elaboration, stoutness, and size), all but curvature lacked phylogenetic signal and showed marked convergence across the phylogeny. We also observed tighter packing of pitchers in crowded conditions, and this effect was most pronounced in curved, slender pitchers.
Conclusions
Overall, our study demonstrates that diversification and convergent evolution of carnivory‐related traits extends to finer evolutionary timescales, reinforcing the notion that ecological specialization may not necessarily be an evolutionary dead end.
