should belong in its own unique family and order. According to the APG IV system, N. nucifera, N. lutea, and their extinct relatives belong in Proteales with the protea flowers due to genetic comparisons. Older systems, such as the Cronquist system, place N. nucifera and its relatives in the order Nymphaeles based on anatomical similarities. According to the APG IV classification, the closest relatives of Nelumbo include the sycamores (Platanaceae). Botany The lotus roots are planted in the pond or river bottom soil, while the leaves float on the water's surface or are held well above it. The flowers are usually found on thick stems rising several centimeters above the leaves. The leaf stalks (petioles) can be up to long, allowing the plant to grow in water to that depth, The peltate leaf blade or lamina can have a horizontal spread of . The leaves may be as large as in diameter, while the showy flowers can be up to in diameter, but fourteen inches (35 centimeters) has been frequently reported. Some cultivated varieties have extraordinary numbers of petals. For example, the Chinese variety qian ban lian ("thousand petals lotus") can have between 3000 and 4000 petals in a single blossom and the Japanese variety ohmi myoren ("strange lotus") can have between 2000 and 5000 petals, the greatest number recorded for any species of plant. Researchers report that the lotus has the remarkable ability to regulate the temperature of its flowers to within a narrow range just as humans and other warmblooded animals do. Roger S. Seymour and Paul Schultze-Motel, physiologists at the University of Adelaide in Australia, found that lotus flowers blooming in the Adelaide Botanic Gardens maintained a temperature of , even when the air temperature dropped to . They suspect the flowers may be doing this to attract coldblooded insect pollinators. Studies published in the journals Nature and Philosophical Transactions: Biological Sciences were in 1996 and 1998 important contributions in the field of thermoregulation in plants. Two other species known to be able to regulate their temperature include Symplocarpus foetidus and Philodendron selloum. Lotus seeds can remain viable after long periods of dormancy. In 1994, a seed from a sacred lotus, dated at roughly 1,300 years old ± 270 years, was successfully germinated. The traditional sacred lotus is only distantly related to Nymphaea caerulea, but possesses similar chemistry. Both Nymphaea caerulea and Nelumbo nucifera contain the alkaloids