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Persian buttercup 



Avi Hirschfield; ASAP 



But in the end, the wild tuhps (and other 

 flowers like them) were what surprised me 

 the most. Tulips had, before this, occa- 

 sionally caught my interest, but only be- 

 cause of their shock value, their superflu- 

 ous show. But these tulips were organisms 

 in an ecological context where everything 

 about them held meaning. If there was 

 show, then that show was important be- 

 yond mere appearance, in the same way 

 that a Hebraic text has significance; it is 

 not just a page of attractive markings. 



The bright red tuUp stuck out like the 

 proverbial sore thumb from the yellows, 

 whites, and blues of the crowd. It offered 

 only pollen, not nectar. The pollen-bearing 

 anthers were almost black, as were the 

 bases of the petals in the center of the cup- 

 shaped flower. 



This color pattern excited me because I 

 had in the previous hour admired very 

 similarly sized, shaped, and colored flow- 

 ers of a quite different plant family. They 

 had belonged to a poppy. The resemblance 

 seemed too close to be accidental. 



With my interest aroused, I examined 

 red flowers more closely in the large 

 patches that were everywhere. I found 

 other red flowers with petals of a red so 

 pure and brilliant they almost made me 

 squint. As it turned out, they were butter- 

 cups. Ranunculus asiaticus, also known as 

 Persian buttercups or scarlet crowfoot. I 

 knew only the yellow-stamened, small 

 waxy yellow R. acris flowers from back 

 home, and these took me by surprise. I 

 found still other flowers that seemed al- 

 most identical to those of the tulips, pop- 

 pies, and buttercups — also large and bowl- 

 shaped, with black stamens, and brilliant 



scarlet petals. These, Avi told me, were 

 crowned anemones. What a contrast to the 

 small, delicate, white-petaled anemones 

 with yellow stamens in a Maine spring 

 woodland! 



A phenomenon so striking as these red 

 flowers — all apparently mimicking one 

 another — had not escaped the attention of 

 local botanists, especially Avi. By 1981 he 

 had already systematically studied and de- 

 scribed the convergent evolution of the 

 "poppy guild" of red flowers in the 



Wild nilip 



Allen Rokach 



Mediterranean region of Israel. The group 

 includes about fifteen species of large, red, 

 bowl-shaped flowers of six genera from 

 three plant families, and is dominated by 

 poppies of two genera. The convergence is 

 most striking when one considers how 

 some of these flowers differ from their 

 likely ancestors. Ranunculus, the butter- 

 cup, for example, has about 400 species 

 worldwide. Only three, all in the Mediter- 

 ranean region, are red. And all of these 

 have cup-shaped flowers at least twice as 

 broad as those of the predominantly yel- 

 low or white species. Wild tulips in Eu- 

 rope are also predominantly yellow, but in 

 the Mediterranean region, red predomi- 

 nates. All poppy guild flowers provide 

 only pollen, and no nectar, whereas some 

 of their presumed progenitors also pro- 

 vided nectar. The various species do not, 

 however, bloom simultaneously. Anem- 

 ones are usually first, followed by tulips, 

 buttercups, and finally, poppies. 



Why did this very distinctive, red, 

 bowl-shaped pollen flower evolve in so 

 many different kinds of plants in one geo- 



graphical area? From behavioral studies of 

 bees, I had speculated that once a pollina- 

 tor becomes "hooked" on one commodity 

 of the market — such as red flowers — it 

 could then be more easily exploited by 

 other plants, provided they are rare or 

 bloom slightly out of phase with their 

 models. It is as if A has developed a market 

 for pizza, but is unable to continue pro- 

 duction after, say, April. In May, B can 

 step in, utilizing an already-established 

 market. If a product is a success, it will be 

 widely copied as closely as possible 

 (given the absence of patent laws). 



But these red flowers are rarely polli- 

 nated by bees. Instead, they are primarily 

 serviced by a group of scarab beetles of 

 the genus Amphiocoma. Beetles had been 

 thought to pollinate only flowers that smell 

 foul and are white or greenish. But in an 

 elegant and classical series of field experi- 

 ments, Amots Dafni, of the University of 

 Haifa, and six colleagues from other insti- 

 tutions reported in 1990 that these beetles 

 have a relatively weak response to shape 

 or scent, but exhibit a strong attraction to 



Crowned anemone 



Bernd Helnrich 



the color red. Dafni and colleagues distrib- 

 uted unscented, flower-shaped plastic cups 

 of vaiious colors (red, blue, yellow, green, 

 brown, white) in the field to serve as bee- 

 tle traps. Of the 146 beedes captured, 127 

 were caught in red flower models. The re- 

 mainder, eighteen beetles, were evenly 

 distributed among the other colors. The re- 

 searchers were also able to confirm their 

 predicdon that the beedes would be found 

 in all of die red flowers of the poppy guild. 

 Amphiocoma likely do most of the polli- 



58 Natural History 5/94 



