Well, if i had to pick one of them, i would pick Victreebel or Exeggutor. Vileplume is average and Sunflora is kind of a dope. I can't really comment on Tangrowth as i am unfamiliar with the Sinnoh pokemo as of yet, but i would put Tangela n the same basket as Vileplume: Not to bad, not the best either. Exeggutor's dual type grass/psychic is quite useful as little is good against nor has a resistance to psychic, however this will give him a x4 super effective against bug. but lets face it, who uses bug types? (Except Bugsy but hes an idiot)
So to sum up, my rankings:
1. Exeggutor
2. Victreebel
3. Tangrowth
4. Vileplume
5. Sunflora
Tangrowth is very similar to meganium, its very bulky It has excellent stats but it is slow and has very little special defense but has enormous defense hp and attack, will easily defeat Bruno
If you can find shroomish in the safari zone, breloom is one of the best plant types. period. It can defeat both Bruno and Karen with few problems, watch out for Karen's houndoom though.
Gloom -> Vileplume Weepinbell -> Victreebell Exegcute -> Exeggutor
Bulbasaur Ivysaur Venasaur Oddish Gloom Vileplume Paras Parasect Bellsprout Weepinbell Victreebel Exeggcute Exeggutor Tengela Bellossom Hoppip Skiploom Jumpluff
Gloom - Vileplume Weepinbell - Victreebel Exeggcute - Exeggutor Nuzleaf - Shiftry Pansage - Simisage Oh, and Eevee evolves into Leafeon at Moss Rock (Eterna Forest in DPPt or Pinwheel Forest in B&W/B&W2)
A leafstone is used to evolve certain grass pokemon. Gloom evolves into vileplume Weepinbell evolves into Victreebel Exeggute evolves into eggecutor Nuzleaf evolves into Shiftry I HOPE THAT HELPED!
The Leaf Stone can only make 5 pokemon evolve. Gloom into Vileplume, Weepingbell into Victreebel, Exeggcute into Exeggcutor, Nuzleaf into Shiftry, and Pansage into Simisage.
Exeggute -> Exeggutor Weepinbell -> Victreebel Gloom -> Vileplume Nuzleaf -> Shiftry
In Pokemon Leaf Green, Exeggcute (into Exeggutor) Gloom (into Vileplume), Weepinbell (into Victreebel)
Gloom --> Vileplume Weepinbell --> Victreebel Exeggcute --> Exeggutor Nuzleaf --> Shiftry
Gloom -> Vileplume Weepinbell -> Victreebell Exegcute -> Exeggutor
Weepinbell-Victreebel Gloom-Vileplume Exeggcute-Exeggutor Nuzelf-Shiftry Yannapu-Yanakki
Leaf Stone Exeggute -> Exeggutor Weepinbell -> Victreebel Gloom -> Vileplume Nuzleaf -> Shiftry
Here is the evolution list for the Leaf Stone. Gloom ----> Vileplume Weepinbell ----> Victreebel Exeggcute ----> Exeggutor Nuzleaf ----> Shiftry
Gloom into Vileplume Weepinbell into Victrebel Exeggcute into Exeggutor and Nuzleaf into Shiftry.
The Leaf Stone may be used on Gloom, (evolving it to Vileplume,) Weepinbell, (evolving it to Victreebel,) and Exeggcute, (evolving it to Exeggutor,) in Pokemon Fire Red.
Bulbasaur Ivysaur Venasaur Oddish Gloom Vileplume Paras Parasect Bellsprout Weepinbell Victreebel Exeggcute Exeggutor Tengela Bellossom Hoppip Skiploom Jumpluff
the Pokemon that evolve with leaf stone are: -gloom into vileplume -weepinbell into victreebel -exeggcute into exegutor -nuzleaf into shiftry I hope this helps i did it out of a completed pokedex. thanks a million :) Approved by KS
When exposed to a Leaf Stone, the following evolve: Gloom into Vileplume. Weepinbell into Victreebel. Exeggcute into Exeggutor. Nuzleaf into Shiftry. Source: http://bulbapedia.bulbagarden.net/wiki/Evolutionary_stone :]