Death by flowers: Giant, suicidal palm has botanists stumped
Jan 18,2008 00:00 by World-Science Staff

A bi­zarre dis­cov­ery has bot­a­nists puz­zled: a new spe­cies of enor­mous palm tree that flow­er’s it­self to death.

Al­though it’s not the first type of plant or tree known to do this, it’s mys­ti­fy­ing re­search­ers for sev­er­al rea­sons. One ques­tion is how such huge trees went un­no­ticed be­fore; an­oth­er is how they evolved and got to Mad­a­gas­car, where they grow.

t. spectabilis, leaving only a thin skeletal structure at the top. (Courtesy J. Dransfield)

Not closely re­lat­ed to oth­er known palms, es­pe­cially there, the tree grows some six sto­ries tall be­fore sprout­ing hun­dreds of suc­cu­lent flow­ers, re­search­ers said in an an­nounce­ment of the find. These drain its nu­tri­ents, they added, lead­ing it to col­lapse in a “macabre” de­mise. 

But the ti­ny flow­ers, which can al­so de­vel­op in­to fruit, at­tract swarms of pol­li­nat­ing in­sects and birds that help en­sure a next genera­t­ion can live. 

The self-im­mo­lat­ing plant, giv­en the sci­en­ti­fic name Ta­hi­na spec­ta­bi­lis, is de­scribed in a pa­per pub­lished Jan. 17 in the Bo­tan­i­cal Jour­nal of the Lin­ne­an So­ci­e­ty. The big­gest palm known in Mad­a­gas­car, re­search­ers said, its fan-leaves alone are as broad as more than half the width of a ten­nis court. 

As the sci­en­tists told it, Xa­vi­er Metz, a French­man who man­ages a cash­ew planta­t­ion in re­mote north­west­ern Mad­a­gas­car, and his family were stroll­ing near­by when they stum­bled across the palm with its mas­sive, py­ram­i­dal bunch of flow­ers at the tip. Their pho­tos soon reached bot­a­nist John Drans­field, hon­or­ary re­search fel­low of Roy­al Bo­tan­ic Gar­dens, Kew, U.K.

“I could hardly be­lieve my eyes,” Drans­field said. It looked “su­per­fi­cially like the­tal­i­pot palm of Sri Lanka, but that had nev­er been recorded for Mad­a­gas­car. Clearly this was go­ing to be an ex­tremely ex­cit­ing dis­cov­ery.” 

He de­ter­mined the im­mense plant was not only a new spe­cies but a new ge­nus, the broad­er cat­e­go­ry that can con­tain one or more spe­cies. The palm does have an “af­fin­ity” with palms of an even wid­er cat­e­go­ry, a “tribe” known as Chu­nio­phoe­ni­ceae, Drans­field added.

This tribe “has an ex­tra­or­di­nary dis­tri­bu­tion,” and it’s hard “to ex­plain how it could ev­er have reached Mad­a­gas­car,” said Drans­field. Oth­er mem­bers of the tribe grow in Ara­bia, Thai­land and Chi­na.

The palm, said Drans­field, was hid­den at the foot of a lime­stone out­crop in the roll­ing hills and flat­lands of Mad­a­gas­car’s Analalava dis­trict. It grows in deep fer­tile soil at the foot of the lime­stone hill in sea­son­ally flood­ed ground, he con­tin­ued, and is so huge it can be seen in Google Earth. 

But it’s still no­where near as high as the tallest trees, red­woods, which reach 300 feet (91 me­ters) or more, com­pared to some 59 feet (18 me­ters) for the palm.

If the plant es­caped no­tice be­fore, it may be thanks to a very long life­span, Drans­field sug­gested; this could make its flow­er­ing-and-death act an ex­tremely rare event, par­tic­u­larly as sci­en­tists es­ti­mate less than 100 of the palms stand. 

“Ever since we started work on [a book] The Palms of Mad­a­gas­car in the 1980s, we have made dis­cov­ery af­ter dis­cov­ery,” said Drans­field, a co-author of that book. “But to me this is probably the most ex­cit­ing.”

The palm’s scar­city pre­s­ents chal­lenges to con­serva­t­ion­ists, es­pe­cially as the hab­i­tat seems so lim­it­ed and flow­er­ing and fruit­ing so rare, he added. “In a way the palm high­lights the con­serva­t­ion chal­lenges for all palms in Mad­a­gas­car, many of which are se­ri­ously threat­ened with ex­tinc­tion mostly through hab­i­tat loss.”

Mad­a­gas­car is a ma­jor hotspot for bio­divers­ity and un­ique spe­cies, in­clud­ing 170 types of palms that are mostly found only there, Drans­field said; but this her­it­age is threat­ened, with only 18 per­cent of its na­tive vegeta­t­ion left in­tact.

Drans­field said he dis­cussed ideas for con­serving the palm with the dis­cov­er­ers and peo­ple from a near­by vil­lage. They set up a vil­lage com­mit­tee to man­age the proj­ect and a pa­trol the palm’s ar­ea, he added. The group is work­ing with Kew and the Mil­len­ni­um Seed Bank in West Sus­sex, U.K., sci­en­tists said, to de­vel­op ways for vil­lagers to sell seed to raise cash and dis­trib­ute the palm to bo­tan­ic gar­dens and grow­ers world­wide.


Courtesy World-science.net