Another species of South American origin today: Santa Cruz water lily is native to Bolivia, Argentina, and Paraguay, where it grows in shallow waterways with little to no flowing water.
Despite leaves measuring 2m (6 ft.) wide, Victoria cruziana is a short-lived perennial, with only a single season’s growth necessary to reach maximum leaf size. Like yesterday’s Pachystachys lutea, it is often treated as an annual planting in cultivation. The preceding link with the scientific name explains the horticultural methods used to propagate the species at Royal Botanic Gardens Kew.
The leaves have a number of adaptations (link also has a photo of the flower). First, they shed water from above easily–you should be able to see the channels on the upper leaf surface leading to openings on the upturned leaf edge. The mass of water from torrential rainfalls is not a problem (nor, for that matter, the weight of a small child). The prominent veins on the underside of the leaf provide strength (likened to poles within a canvas tent) and stability (like a deep-treaded tire compared to a bald one). But there’s more–the veins are also dotted with spines for protection. One wonders if the spines are for any extant organism or something in the distant past–the Nymphaeaceae are among the most ancient of flowering plant lineages.
Similar to magnolias, Victoria cruziana is pollinated by beetles. Another adaptation is evident here: thermogenesis, a chemically-induced heat-generating process that volatilizes the floral scent to better broadcast it. If these plants didn’t occur in subtropical regions, I’d speculate that the heat was also a secondary reward for the beetles (helping them be more active), but I suspect that isn’t necessary in this instance.
The species is named in honour of Andrés de Santa Cruz, who sponsored the expedition in Bolivia in which this species was first discovered for Western science.