More proof that monster traits at WotC are decided by randomly matching abilities and types: the tendriculos is a giant plant with regeneration overcome by bludgeoning damage. I feel like this monster's name rhymes with 'ridiculous' for a reason.
It's chassis isn't that great either. 9 plant RHD, four negative stat modifiers and a low movement speed for something Huge-sized. High strength and dexterity are welcome, as is the 15 ft. reach, but only three natural attacks are lackluster again, especially when the best one will most likely end up as a mouthpick-holder.
As for special abilities, there's Regeneration 10 (overcome by either bludgeoning or acid damage), Improved Grab (technically works with all three attacks, but requires a free mouth), and Swallow Whole, which comes with a spiffy paralysis effect (though being restricted to swallowed creatures hurts its power) and 2d6 acid damage a round (that's right, one of the monster's two specific weaknesses is continuously produced in its stomach).
All things considered, I don't think the tendriculos is worthy of a positive LA. It's a big dumb melee brute that focuses on a sub-par strategy (grappling) with bad hit dice and frankly no real advancement options I can see. If you want to be huge and strong so badly, there's other options out there. Perhaps a +0 could be argued, but I don't see it to be honest.