![IMG_20111210_105405.jpg](/data/attachments/1359/1359199-58f201f7ae53ff3091c9d47e7d602364.jpg)
I have a plant that has a brown spots and lines on the stem almost like a thin crust but not quite. Any ideas why this is happening? the rest of the plant, leaves and all are a healthy green color, no yellowing or other signs of ph problems. (hard to see in the picture, but look at the dark areas on stem)