Why do Nightshades have bonus HP?

[GreatDane]

[Nightshades on the SRD (http://www.d20srd.org/srd/monsters/nightshade.htm)]

Pretty much what it says on the tin. As undead, nightshades don't have a Con score. They also don't have Unholy Toughness, which lets them use their Charisma instead of their Constitution for bonus hit points. So what gives? Did I miss a note somewhere in their description? Is this just an error?

[OldTrees1]

Check the 3.0 rules for undead(AFB myself) and you might find out why this typo occurred.

Of course, undead can be made with bonus hp, but that is normally a modification to the base stats.
Edit: Failure to read throughly

[Azoth]

Desecrating Aura (Su)
All nightshades give off a 20-foot radius emanation of utter desecration, imbuing their surroundings with negative energy. This ability works much like a desecrate spell, except that the nightshade’s evil is so great that it is treated as the shrine of an evil power. All undead within 20 feet of the nightshade (including the creature itself) gain a +2 profane bonus on attack rolls, damage rolls, and saving throws, and +2 hit points per HD. (The nightshade Hit Dice, attack, and save entries given here include these profane bonuses.)

Bolded part explains it for you.

[Glimbur]

Their Desecrating Aura gives +2 hp per hit die to all undead around them, including themselves.

[GreatDane]

The aura would do it. I forgot that was already figured into their statistics. Thanks, Playground!