the thread started by Dr bill, on Punjab, (which seems to be the land of the five rivers,) changed directions . but i kept thinking about it..
http://wordsmith.org/board/showflat.pl?Cat=&Board=weeklythemes&Number=81002
Mesapotamia came up, i.e., the land between the two rivers, and i thought of hippopotamus, (horse of the river, or more commonly river horse with the potumos ending meaning river.. and i wondered how river and feather had the same root -- and looked it up, here is the link,
http://www.bartleby.com/61/roots/IE405.html
and wow, what a list of words !
The commonality seems to be rapid movement -- (to fly, to rush,) and from there many movement words, and feather related words... ) and while there are many links, i can think of one or two words related to the root that are not listed.. and i suspect others can add more! but even the ones what are listed , offer a wealth of fun.

what does panache Dash, Verve have to do with ptomaine a nitrogenous organic compound produced by bacterial putrefaction ?

the text below, is incomplete, since images of some of the symbols used don't copy well.. and the original has many links..

Pet(symbol)-
Also pet- (oldest form *pet1-). To rush, fly. Variant *pte1-, contracted to *pt-. Derivatives include feather, compete, perpetual, ptomaine, symptom, and hippopotamus. 1. Suffixed form *pet-r-. feather, from Old English fether, feather, from Germanic *fethr, feather. 2. –petal, petition, petulant; appetite, compete, impetigo, impetuous, impetus, perpetual, repeat, from Latin petere, to go toward, seek. 3. Suffixed form *pet-n-. panache, pen1, penna, pennate, pennon, pin, pinna, pinnacle, pinnate, pinnati-, pinnule; empennage, from Latin penna, pinna, feather, wing. 4. Suffixed form *pet-ro- in compound *aku-petro- (see ku-). 5. Suffixed form *pet-yo-. propitious, from Latin propitius, favorable, gracious, originally a religious term meaning “falling or rushing forward,” hence “eager,” “well-disposed” (said of the gods; pr-, forward; see per1). 6. Suffixed zero-grade form *pt-ero-. –pter; acanthopterygian, aminopterin, apteryx, archaeopteryx, coleopteran, dipteral, mecopteran, orthopteran, peripteral, plecopteran, pteridology, pterygoid, sauropterygian, from Greek pteron, feather, wing, and pterux, wing. 7. Suffixed zero-grade form *pt-ilo-. coleoptile, from Greek ptilon, soft feathers, down, plume. 8. Suffixed variant form *pt-no-. stearoptene, from Greek ptnos, winged, flying. 9. Reduplicated form *pi-pt-. ptomaine, ptosis; asymptote, peripeteia, proptosis, symptom, from Greek piptein, to fall, with verbal adjective pttos (< pt-to-), falling, fallen, and nominal derivatives ptsis (< *pt-ti-), a fall, and ptm (< *pt-m), a fall, fallen body, corpse. 10. O-grade form *pot-. hippopotamus, potamology, from Greek potamos “rushing water,” river (-amo-, Greek suffix). 11. Suffixed form *pet-tro-. talipot, from Sanskrit pattram, feather, leaf. (Pokorny 2. pet- 825.)


my other obsession