We have this potted plant indoors that we bought in a garden shop about a year ago. It is now getting sick, so I am trying to research how to treat it. However, first I would like to know which species it even is. Can anyone help?
It looks like a plumeria, by the shape of the leaves. It's an outdoor plant and needs lots of sun. If you have the space, I would put it outdoors.
It looks like a Corokia cotoneaster. I think yours is too gone to treat. I think it was overwatered. See if it is waterlogged. Does that pot have holes in the bottom. If not get it a new pot. But, I would start over with a new plant. Those small leaves can easily dry out, but they are known to be drought resistant. There is the possibility that the leaves just dried out and the plant will leaf out again. I personally have never seen a Corokia grown as an indoor plant. They are not the hardiest of all plants only cold hardy to Zone 8, but I have no experience growing them indoor. I have grown them in pots outdoor and have dried them out to the point of no return, because plants are only drought resistant in the ground not in a pot. I have also seen them desiccated by cold winds. Do you have a heat vent or radiator near by that could have dried out the plant? Feature on growing Corokia in the PNW by the University of Washington