There is much confusion about poison sumac, Toxicodendron vernix (L.) Kuntze., because the common name is used interchangeably for poison-ivy, T. radicans (L.) Kuntze., and poison-oak, T. pubescens Mill., because all three cause the same contact dermatitis due to urushiol , the offending chemical that may be 4 to 20 times more concentrated in poison sumac.  Additionally may  people do not  recognize poison sumac as being distinct from sumac species in the genus Rhus L. that  are not toxic.  The common name thunderwood furthers the confusion since it is applied to both poison sumac and sourwood, Oxydendrum arboreum (L.) DC., because the later crackles explosively when burned.  Poison sumac, shown here, has pinnately compound leaves  with 9-13 leaflets unlike the trifoliolate leaves of poison-ivy and poision-oak  All of these have a good fall color ranging from yellow to red.  The toxic species all have green axillary flowers that produce white/cream colored drupes while the non-toxic species in the genus Rhus all have terminal clusters of red fuzzy drupes that taste like pink lemon-aid.  Furthermore the habitat of Rhus tends to be much drier while poison sumac is an obligate wetland species. Poison sumac is relatively rare in northeast Alabama due to a natural range gap throughout much of Tennessee and Kentucky where it is endangered.  Interestingly the pictured plant is from the first recorded population in Jackson County, but the largest specimen in the population was killed when a tree fell on it during a hurricane thus an Alabama Champion Tree nomination was withdrawn until either another specimen reaches the minimum required size or a larger champion is named.  For obvious reasons poison sumac is probably not available as a landscape plant although the fall color is excellent and it could be a better deterrent to criminals than sticker bushes since they could  possibley be identified later due to being incrimnated by the resulting rash.