Wow lots of interesting stuff here! I think there are multiple issues here, and, since the health of the plants isn't great, I would deal with all possible problems rather than hunt down one specific one. If it were me I would do the following, since doing them would fix any of the most likely problems that you may be having. I would change the mix to a free draining one. I would check the roots, and pot into a container that is only a little larger than the rootball. I would put them in a partially sunny position after the repot until they get used to their new mix and pot. I would then move to a sunny location once things started to settle. I would make sure the room had plenty of humidity with gravel trays or a humidity. I would make sure the room was warm, and provide bottom heat to the pots if possible. I would inspect for bugs. Mites and scale seem the most prolific - possibly mites in your case. Webbing is a telltale sign, and sometimes hard to spot, but not always present. I would treat with Toni's spray regardless (she can tell you the ingredients, or you can search previous posts.) If you do spot bugs, use Toni's spray or a suitable one for fruiting plants from a garden centre. I would water these (after the repot) only when the new medium was closer to dry than damp. In a new medium you won't have to worry so much over watering - if it is the right medium it is unlikely you will overwater unless you go nuts with it. Fertilize only very lightly until the tree is back to health, then feed with a high nitrogen feed every couple of weeks. Citrus bounce back, but they take time. These are not by any means the be all and end all of things you should do, they are merely what I personally would do :) Danny

It's an epiphyllum, probably an epiphyllum hybrid (which typically contain other, similar genera, including Disocactus, Pseudorhipsalis and Selenicereus). These are commonly referred to as 'orchid cactus', but they are neither a true cactus nor an orchid :-) They are a semi-tropical succulent related to cactus that produces large, very showy flowers. They do produce an edible fruit (NOT a dragon fruit) but these are scarce on indoor plants. They are epiphytes, meaning they take advantage of other, larger plants - like trees - as a support system, like most tropical orchids do, and do not require soil in their native habitat. For home gardeners, they grow perfectly well in a good quality, fast draining potting mix. Unless you live in a semi-tropical climate or certainly a frost free zone (Z 10 or higher), these are not hardy outdoor. And they are pendant in habit, with those long branching structures cascading over the side of a container to often a significant length. One normally grows them in some sort of hanging basket structure or on a tall plant stand to show off the plant and its long branches to best effect. btw, the flowers form at the tips of these flattened leaves/branches so any pruning should be done cautiously. There are scads of websites on epis and if you do a bit of searching, they will provide all the growing info you need (rather than my repeating it all here!!). I find they are very easy to grow and will reward you with some gorgeous - if short-lived - flowers. I've got one setting flower buds now after being moved back indoors from its summer holiday location. Here's just one example of an epiphyllum website but do not stop with just one!! And be sure to check out any that show photo galleries of the blossoms - they are incredible!!

It is a weedy Persicaria that you need to remove asap. At least cut off the flowering stems before they go to seed if you can't pull/dig them all right away.

The 2nd one looks like a Plectranthus. I don't know which species turns red in tons of sun, maybe neochilius. Are you able to add a closer pic of the bloom? The first one gave me a Plectranthus vibe too, but could be something in Crassulaceae. Is it fuzzy?