Plant Biology Answers: Nymphea Leaf Hydrophytic And Cactus Xerophytic Growth Environment

While a thorough description of how a Nymphea leaf's adaptation which allows it to grow within the hydrophytic environment can be exhaustively scientific, a basic explanation in terms of biology is given herein. One obvious key to their wondrous adaptation is the fact that hydrophytes do not contend with water loss problems like wilting, drought, or transpiration. Biology research experts and journal authors describe the growth process as involving a buried shoot system, not relying on traditional seed-soil germination, and remains in underwater sediments “throughout the life of the plant” and tender young leaves burgeon from the rhizome and “mature into three leaf types,” identified as immersed, surface, or aerial (Villani and Etnier 177). Professors and biology teachers at Tutorvista break down a further understanding in revealing that hydrophytes can be classified into 6 groups which are as follows: a) Free-floating, b) Rooted with floating leaves, c) Submerged floating, d) Submerged and rooted, e) Amphibious and rooted, and f) Emergent and rooted. The Nymphea leaf grows in the specialized category of the “Rooted with Floating Leaves” category. 

How it works is that the Nymphea roots are actually attached to the bottom where they remain. The leaves' specially created “biomechanical properties” of the long petioles allow it to keep the leaves float on the water's surface, but authors admit “little is known about the causal factors determining their appearance” (Villani and Etnier 178). Researchers Suresh, Matthew, Al-Zalzaleh, and Al-Menaie state that freshwater provides the best performance for growth, and that fertilizers must not exceed “assimilative capacity” (Suresh et al. 103).  Additionally, the presence of fragrances has been shown to inhibit growth. Whether a surface floating apparatus or a hanging aerial variety the fascinating growth adaptations of the Nymphea leaf keep scientists ever investigating and horticultural lovers in awe of their natural beauty. 

In the second part of the inquiry regarding adaptations of the cactus, in terms of what allows it to grow in the xerophytic environment can be explained in rather straightforward terms, too. To avoid getting bogged down with excessively detailed analysis, such as involving genetic variability or “modern genetic differentiation among populations,” as can be more adequately explained by peer-reviewed journal authors Mateus and Sene it is best to cut directly to the point (136). Once again as in the above model of the Nymphea description, the adaptation lies in the root-stem-leave system. Unlike the Nymphea plant types, Xerophytes are designed to live and thrive in dry environments. One distinguishing feature that allows its growth in such thirsty, dry conditions is a cactus's extra-thick epidermis which “decreases water loss,” and a special “palisade mesophyll” tissue which deflects light intensity thereby avoiding “potentially drying photosynthetic tissues.” In the case of cacti spines, then, or its stickers as commonly referred to in lay terms – it is obvious that any photosynthesis activity would be restricted to the body or succulent types which store water in the fat leaves. 

The same aforementioned source describes sunken chambers of stomata that rapidly take up or ingest carbon dioxide, for instance during heavy rain or during a rare wet period of high humidity. So you can imagine any cactus with a large number of stomata would have a great propensity to survive their dusty, heated climate. Beyond the stomata in the leaves, the cactus root system is capable of tapping deep water sources, while a “thick waxy cuticle” of the stem protects from water loss. Large succulent cacti such as the saguaro are a sight to behold when in bloom across the desert.        

Works Cited

Mateus, R. P., and F. M. Sene. “Population Genetic Study Of Allozyme Variation In Natural Populations Of Drosophila Antonietae (Insecta, Diptera).” Journal Of Zoological Systematics & Evolutionary Research, vol. 45, no. 2, 2007, pp. 136-143. 

Suresh, N., et al. “Influence Of Water Quality On The Growth Of Waterlily Varieties (Nymphaea Sp.”In Kuwait.” International Journal Of Academic Research, vol. 3, no. 4, 2011, pp. 103-107. 

Villani, Philip J., and Shelley A. Etnier. “Natural History Of Heterophylly in Nymphaea Odorata ssp.Tuberosa (Nymphaeaceae)', Northeastern Naturalist, vol. 15, no. 2, 2008, pp. 177-188.