Rosemary looking plant

[socer03dud]

About a Month ago A green plant began growing in my aquarium. I'll try to get a picture of it for you all to see. But i'll try describing it. I looks kind of like rosemary, the herb. I has thin long green 'branches' it also grows quite rapidly. I was just wondering if it is good or bad and what it is. Thanks

 

[socer03dud]

well my camera won't focus on the plant. But i did get a closer look at it. and it looks kinda like feathers, it's also soft.

 

[dogstar]

Caulerpa sp.
several that look like you described. Its OK to have it and some fish like Tangs will feed on it but it can get out of control and take over quick if you let it.