A Final Six Plants I'm Not Currently Mad At (Po through Z)

And now, the thrilling conclusion of the plants-I'm-not-currently-mad-at series. (A-G is here; H-Pn is here.)


1. Podocarpus macrophyllus

Podocarpus has died several times under my care already, and may again, but we're getting along for the moment. This one's my longest-lived yet. (Two and a half years!)

Date: September 2012.
Pot size: 4.5" / 11.5 cm?
The problem is always watering: let a Podocarpus get too dry, and you will have an unhappy Podocarpus. My solution to this has been to keep mine in a larger pot than I normally would (I repotted shortly after the above photo was taken, in fact), and to water every time its turn comes around in the watering cycle (i.e. every two weeks), whether it feels dry or not.¹

Date: April 2010.
Pot size: 4" / 10 cm.
Otherwise, not that big of a deal. I have a faint recollection of mealybugs or scale in the recent past, but I'm not sure if that's something that actually happened or just something I was dreading really vividly. It's been happy with artificial light so far, and has lived in the basement since its arrival, so the cooler temperature and higher humidity down there may be contributing to its non-death.

In any case, this is a plant that really shouldn't be working out for me, but it nevertheless is. At the moment. We'll see how that goes.


2. Polyscias fruticosa

As nervous as I was about buying Polyscias fruticosa, it's turned out to be a really reliable, good plant. They have a reputation for being temperamental, though this is probably more about them preferring consistency. Don't move it around a lot, and give it dependable water, and it should be fine.

Date: September 2012.
Pot size: 12" / 31 cm.
They're also surprisingly fast growers, when they feel like it. This plant has at least tripled in height in the three and a half years it's lived here. (I'm actually starting to worry that it might outgrow its spot!)

Date: May 2010?
Pot size: 6" / 15 cm.
I've had it in an east window for at least a couple years. It's been getting water every two weeks, plus a generous amount of fertilizer (year-round), but that's going to have to change, since I moved it into a larger pot a month ago. Watering will probably be more like once a month now.

It's never had any pests, and defoliated dramatically only once, this last summer. I think that was because it had gotten pretty rootbound, and was drying out too quickly, though it's also possible that the top leaves had just become so abundant that the leaves at the bottom were getting shaded out. Only the bottom leaves dropped, and not terribly many of them.


3. Rhapis excelsa

Rhapis excelsa is exactly the kind of plant I'm wanting to spotlight with these posts. I all but forget that I have it, because it never does anything terribly dramatic. It doesn't even need watering as often as most of the plants. It doesn't bloom, it grows really slowly, it holds on to its leaves, it suckers sluggishly -- there's really no reason to ever notice it. It even looks pretty much the same now as it did when I first got it:

Date: September 2012.
Pot size: 8" / 20 cm.
Date: March 2008.
Pot size: 6" / 15 cm.
At the same time, though, this is actually what a lot of people are looking for in a houseplant.² And even if it's not six times the size it used to be, there's a lot to be said for a plant that will just mind its own business and grow without getting bugs or requiring pruning or whatever.

The only complaint I have about Rhapis is that the leaf tips used to burn on me. They've stopped, since the plant got relocated to a cooler, darker spot, but it's not clear whether the change in temperature and light fixed the tip-burn problem or if it was something else entirely.³ Presently, it's in the basement, on the floor, where it gets heavily filtered light from some of the shop lights (though it doesn't have its own shop light) and some indirect sun, on the days when we have sun. I water it about every 4 or 6 weeks, and fertilize lightly year-round. I've yet to see any pests on it. I would love, love, love to propagate R. excelsa, but it grows so slowly, and propagation is so uncertain, that I haven't been willing to take the gamble yet.


4. Stapelia gigantea

S. gigantea is another plant like Plectranthus verticillatus, that's gotten smaller since I've had it; in this case, the reduction occurred because I cut off a big chunk of it for cuttings. (If I remember correctly, all the cuttings were successful. They're more wrinkled than the parent, and floppier, which is worrisome, but all are still alive, and most are now producing new growth.)

Date: September 2012.
Pot size: 6" / 15 cm.
The flowers are certainly interesting, though not necessarily the main thing I like about the plant. It scores points with me mostly for its tactile qualities, not so much its appearance (though the appearance is cool) or the flowers' smell (which is in fact unpleasant, though not as terrible as I'd been led to believe it would be). That, and it's easy to grow.

Date: September 2009.
Pot size: 6" / 15 cm.
My plant has been in a west window since I've owned it, not counting a brief period when it first arrived and I had it outside. (A bad idea: it burned.⁴) It would probably prefer a bit more light than that, but that's as good as I can do, and it seems to be able to get by on that. The cuttings are all downstairs under artificial light, which is even less bright than a west window, and they do okay, though it's worth noting that they aren't growing very fast.

The parent plant gets watered every time the watering cycle comes around, every two weeks; the cuttings get water more like every three or four weeks, but it's colder in the basement, and they aren't getting as much light, and they're in plastic pots, so that makes sense. I fertilize year-round. Sources elsewhere on the internet tell me not to let the temperature go below about 50-55F (10-13C), but neither the plant room nor the basement normally get that cold, so temperature and humidity aren't much of an issue. There have never been any pest problems; I've been watching for scale lately (because the cuttings are in that neighborhood of the basement), but so far I haven't seen any.


5. Stenocereus thurberi

Stenocereus thurberi was one of the plants I was offering for sale in the spring this year, because even though I liked the look of it, I didn't seem to have enough light to convince it to grow. Nobody was interested, though, so when I ended the plant-selling, the S. thurberi went outside, and once it was out there, it did produce some new growth.

Date: September 2012.
Pot size: 4" / 10 cm.
It's not dramatic new growth, of course. You would be forgiven for not noticing that the two pictures were different. But the top two or three areoles on each rib above is new growth as of this summer, and I've had the plant for almost three years. So it's a big deal to me.

Date: December 2009.
Pot size: 3" / 7.5 cm (along diagonal).
Other than its unreasonably high demand for light, S. thurberi has been easy enough to grow indoors: I try to keep it drier and reduce fertilizer in the winter, though I still water about every 4-6 weeks.

I suppose it's a little odd to praise a plant for not growing, but that's basically what I'm doing here: I've thrown out cacti that grew while not getting enough light,⁵ because the new growth is small, pale, and weak, and even when given better conditions afterward, plants don't necessarily fill in the spindly growth.⁶ So it's actually good if a plant refuses to grow for three years because it doesn't have enough light. Hopefully it won't keep growing this winter out of some misguided biological momentum or something.


6. Zamia furfuracea (?)

I repotted Z. furfuracea (or whatever it is⁷) in August, because it had been in the same 4-inch (10 cm) clay pot for a few years. It turned out that it did need to be repotted, but it's also lost a few leaves since then, which is something it basically never did before. It's also growing much larger new leaves now, so it's fine: the point is just that after a long period of being a good, stable plant for me, it's starting to undergo some Changes, and we don't yet know for sure how that's going to turn out.

Date: September 2012.
Pot size: 6" / 15 cm.
That said, though, I have no complaints with it so far. It's been fine close to an east window. It used to get watered every two weeks; I think so far I've continued to do that, post-repotting, but it may slow down to every four weeks in the winter, depending on how quickly it seems to be drying out. Neither temperature nor humidity are likely to be an issue to someone growing it indoors, and I've never had pest problems on mine.⁸

Date: October 2009.
Pot size: 4" / 10 cm.

Also relatively non-upsetting:

Sansevieria cylindrica
Sansevieria hargesiana
Scindapsus pictus
Selenicereus chrysocardium
Stenocereus pruinosus
Stromanthe sanguinea 'Triostar'
Tradescantia spathacea
Vriesea imperialis

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¹ Is it possible to overwater a Podocarpus? Probably. I have one houseplant book that says they're prone to root rot if they're kept too wet or left to stand in water. It's not something I've ever seen personally, though.
² My recollection, from the garden center days, is that the houseplant every customer is looking for:
• has large, shiny, mostly-green leaves, with optional variegation,
• needs almost no light at all,
• produces huge flowers, year-round, in any shade of any color desired,
• is pleasantly- but not overpoweringly-scented,
• never needs fertilizer or repotting,
• is nontoxic to pets and children,
• and will grow to the height of exactly six feet (1.8 m) tall and then stop getting taller.
It takes a few months, but one does eventually get used to disappointing the customers.
³ The old spot was also in the basement, so things like temperature and humidity should have been more or less the same; the main difference between the two situations is that the first location had a shop light directly over the plant. I'm also fertilizing more now, but it would be weird if that was responsible: ordinarily if there's a tip-burn problem on a plant, more fertilizer will make it worse, not better.
⁴ They can, of course, grow outside in the sun: I just didn't try as hard as I could have to acclimate it gradually. It had most likely been growing inside on someone's windowsill before they brought it to the consignment store, so it would have been accustomed to lower light.
⁵ Specifically: Parodia microsperma and Echinocactus grusonii.
⁶ Some do, some don't: I have some mildly etiolated Myrtillocactus geometrizans that grew some weak new growth after arriving here, but they spent the summer outside this year and managed to fill in somewhat. They still don't look quite right: the newest growth is disproportionately big compared to the growth that immediately preceded it --

-- but the stems also thickened up a little bit, enough so that I'm optimistic that the plants will even themselves out eventually.
⁷ I'm positive that it's a Zamia; I just don't know which one.
⁸ I know they can get scale, though: when I worked at the garden center, we threw out a batch of Zamias (not necessarily the same species as mine) because they developed a bad scale infestation. Which was depressing: up to that point, I had been considering buying one of them for myself.

List: Houseplants Which are Partly or Totally Blue

Well okay. "Blue" is a stretch. Though a few genuinely blue plants are rumored to exist (Micorsorum steerii, an unknown Begonia species), one, they're iridescent, and change color depending on the angle at which they're being viewed, and two, it'd be a stretch to call them houseplants, since the Begonia isn't even in cultivation as far as I know, and the Microsorum is cultivated but not really suitable for the home outside of a terrarium. And maybe not inside a terrarium, either. I don't know anyone who's tried.

But there are still plants out there with some blue to them. Most are succulents, and the blue coloring is the result of a fine, powdery layer of wax covering the leaves and/or stems, which is confusingly called "bloom." The main purpose of bloom is to reflect excess light (especially ultraviolet) and heat away from the plant, which is why it's common on desert plants, but it also, being wax, is water-repellent, so other kinds of plants find uses for it as well (for example: the leaves of some varieties of cabbage; the leaves, stems, and seed pods of poppies; fruits of grapes and certain other fruits).

Because bloom serves a self-shading purpose in a lot of the plants in which it is found, plants grown indoors may not produce as much, and may as a result appear more green than plants of the same type grown outdoors. Bloom also rubs off easily when plants are handled, so if you value the color, try to touch the leaves as little as possible. On the other hand, some plants may change color if they're in very bright light (such as full sun outdoors): many Aloes, for example, will turn red or brown-red in full sun. Others will stay blue or green but will get reddish leaf margins.

Because there's no good way to define "blue" for these purposes, and because plants grown in different conditions may look different, I don't guarantee that you'll agree with my choices here, but I did search davesgarden.com for "blue," all 75 pages of results, so I'm trying to cast a wide net. (I also got to look at a ton of purple daylilies and potatoes, which makes me think that hort types have a broad and flexible understanding of the meaning of the word "blue" anyway.) Please note also that I'm excluding plants with blue flowers from consideration: here we're only thinking about leaves and stems. If I can come up with ten houseplants with blue flowers, and that's a big if, then blue-flowering plants will get their own list someday.

Agave x 'Blue Glow.' Leaves are pretty consistently turquoise to blue; marginal spines may be yellow, orange, or red depending on light, and are sometimes all three colors at once.

Aloe brevifolia. In outdoor sun, plants have a tendency to turn different colors: depending on the photo, they may be bronze, purple, or gray. My plant doesn't get much direct sun, and it has been light blue-green pretty much the whole time I've had it.

Browningia hertlingiana. Photos show variable color, but from what I can tell, the color tends to be a pretty solid turquoise/blue.

Echeveria cvv. (some cvv.) The blue cultivars tend to be a fairly pale, washed-out, greenish-blue, often with pink or red leaf tips.

Juniperus sp. Variable color depending on species, photography, and culture, but I think it's close enough to count.

Melocactus azureus. Quite a few pictures that turned up in Google image search looked pretty plain green, no blue at all, but the one in this picture really was as blue as shown. I assume either cultural differences or misidentifications.

Myrtillocactus geometrizans. The picture does a terrible, terrible job of illustrating the color (though it does show how the bloom rubs off with handling), but Myrtillocactus is typically a vivid blue-green.

Phlebodium aureum 'Mandianum.' New fronds in particular tend to be a dull blue-gray. My personal plant is a lot more yellow-green now than it was when I bought it, probably because of inadequate light, but the new fronds still emerge bluish.

Sedum morganianum. Plants kept in insufficient light will be greener. The real color is less saturated than that in the photo.

Selaginella uncinata. The blue color is due to iridescence. I don't know what these do in lower light.

On the do/don't recommends:

I do recommend Agave 'Blue Glow,' which has done fine for me so far under lights in the basement. It's unclear whether it's going to be a particularly good long-term indoor plant, and I'm aware they can get very large, which is a worry, but so far, so good.

Sedum morganianum is a favorite plant of mine: I was worried, after Sedum x rubrotinctum always seemed to be reaching for more light, that I wouldn't be able to grow S. morganianum, but my plant has been in a west window since the move, and it's been one of my better-behaved plants. It does drop leaves every time I water it: they're loosely attached to the stem, and come off easily. After trying for a while to prevent this from happening, I've decided to just accept that it will, and start new plants with the leaves that come off. As a result, we currently live with five pots of Sedum morganianum, and I expect there will be more coming along all the time.

The third recommend is Aloe brevifolia. It's not my most exciting plant, but it's been steady and unproblematic, and I've had it for a very long time (relatively speaking), so it wins out over the various plants in this list that I haven't had for very long or that haven't done much of anything (Browningia, Myrtillocactus, Phlebodium) or the nice-seeming plant I've never had at all (Melocactus).

For the un-recommend, I'm torn between Juniperus and Selaginella. Both are pretty inappropriate for your average indoor houseplant-grower, though for different reasons: Juniperus wants cooler temperatures, especially during the winter, and Selaginella is unforgiving of missed waterings and dry air. I suppose most people who received both at once would kill the Selaginella first, so if I have to choose, then Selaginella is the anti-recommend.

Not pictured:

• Several other Agave species and hybrids are blue to some degree or another; I'm particularly fond of the plant I think might be A. desmettiana.
• Many, many Aloe species and hybrids, including A. 'Blue Elf,' A. maculata, A. striata, A. vera, and A. 'Walmsley's Blue,' are bluish-green.
• Bismarckia nobilis is perhaps a little large and demanding to work as an indoor plant, but I've heard of people making the attempt, and it's sort of a silvery-blue in good conditions.
• Cereus aethiops varies a great deal in photos, but looks like it tends to be somewhere in the blue/green part of the spectrum most of the time.
  
• Chamaedorea cataractum, when grown in good conditions, has a metallic blue sheen to some of the fronds, though I expect that fades when grown indoors.
• Chamaedorea metallica has a sort of dull blue-gray color under some conditions.
• I'm not sure it makes a great houseplant, but the blue Mediterranean fan palm, Chamaerops humilis var. argentea, shows up as silvery blue in some photos.
• Crassula arborescens var. undulatifolia (sometimes sold as C. 'Blue Bird') is slightly bluish under strong light, and plain green under lower light.
• Also maybe not great houseplants: Cycas angulata (silvery-blue) and C. ophiolitica (slightly bluish green). The related cycads Encephalartos arenarius (highly variable, according to the pictures: olive green, blue-green, silvery) and E. horridus (much more uniformly silver-gray, with hints of blue) would also technically qualify.
  
• Dasylirion berlandieri and D. wheeleri are both bluish-gray, and I've seen D. wheeleri, at least, sold as a houseplant. No idea how well that works out for people.
• Echinocactus horizonthalonius is a dull, mostly gray shade of blue under some conditions.
• I'm not sure I believe in the existence of Epipremnum aureum 'Cebu Blue' or not, and if it does exist, I'm not sure it qualifies as blue except in name. Can't tell much from the photos.
• A number of Ferocactus spp. are blue or grayish-blue.
• Haworthia limifolia var. ubomboensis is mostly green, but with a hint of blue or blue-gray, depending on conditions and photography. A few other Haworthia species are also sometimes bluish, though they tend to be green or gray.
  
• Kalanchoe eriophylla is, according to davesgarden.com, given the common name of "Blue Kalanchoe," though it's more white than anything -- I'm not sure I see it.
• The younger leaves of Kalanchoe luciae and K. thyrsiflora are covered with a light bluish bloom, though it's temporary and not particularly intense.
• Kalanchoe marmorata is bluish-green or bluish-gray in good light.
• Kalanchoe tomentosa varies according to photography and growing conditions, but are sometimes gray-blue or blue-green.
• I found it a very disappointing houseplant, but Lamprathus blandus has lots of oddly-shaped leaves that can appear as blue, green, gray, or intermediate shades thereof.
• Leuchtenbergia principis is a bizarre cactus with blue-gray projections which resemble leaves. In strong light, the "leaves" will be edged with reddish-purple.
• Several cultivated Lithops varieties are blue-green or blue-gray.
• Microsorum steerii and M. thailandicum are both apparently a striking, deep, iridescent blue/green/black; whether they can be grown indoors is questionable.
• Several Opuntia species are blue-green, blue-gray, or blue-violet at certain points in the year, though since the most dramatic color is brought about by cold, a plant raised indoors year-round is unlikely to exhibit the full range of color.
• Some cultivars of Pachyphytum, xPachyveria, and xGraptoveria are blue, gray, or violet to some degree or another.
• Davesgarden.com lists a Peperomia 'Blue Whale,' which the photos make look mostly black, but I suppose it could plausibly be blue.
• Pilosocereus pachycladus is a washed-out bluish-gray.
• Sedum burrito is very similar to S. morganianum, pictured above, though the leaves are more rounded and are more perpendicular to the stem.
• Senecio crassissimus has red-edged blue-gray leaves when grown in bright enough light.
  
• I've never seen Senecio serpens and S. talinoides attempted indoors, but we did keep an S. talinoides (I think) in the greenhouse over a winter at work, and it grew okay. Possibly you'd have to use supplemental lighting. Both are powdery blue or blue-gray.

List: Houseplants Which Could, In Theory, One Day Produce Something Edible, Perhaps

Lots and lots of caveats for this one.

1. I could be mistaken. I've collected what appears to be good information from knowledgeable sources, but they could be wrong, I could have been looking at the wrong line on the page, etc.

2. You might not have the identity of your plant correct, even if I do.

3. Just because some part of the plant may be edible, it does not necessarily follow that the rest of the plant is safe to eat.

4. Even if you and I have both identified the plant correctly and I have good information regarding the edibility, some "edible" plants are poisonous if not prepared in a certain way. Some things have to be cooked first. Some things have to be washed and filtered and washed again, and so forth. Some fruits are incredibly nasty if you try to eat them before they're ripe. And so forth. So don't just assume you know how to prepare it.

5. Even if I'm right about the identity of the plant, and you're right about the identity of the plant, and I've located good information about which parts are edible and under what circumstances, and you prepare the plant properly, if the plant hasn't been in your care for a reasonably long time, it may still have been sprayed with pesticides of some kind and be unfit to eat. Unless you know where it's been, don't assume you can eat it.

6. I also have to qualify this list by adding "in theory" and "someday." In general, tropical houseplants need to be fairly old, large, and healthy before they will flower and fruit, which is fairly difficult to pull off in normal home conditions. One stands a better chance, obviously, with leaves.

7. Even if you manage to get a plant to the point where it bears fruit indoors, or whatever, and you know for sure what plant it is, and I've identified it correctly, and I was working from good information, and you prepare it correctly, and it's been yours for long enough that pesticides aren't a problem, you may find that the fruit (or whatever), when eaten, is not particularly good, compared to the sorts of stuff you could get from the supermarket.

8. And you could be unlucky enough to have an allergic reaction to the plant anyway.

But! Hypothetically! If you were locked in a tropical botanical garden or garden center greenhouse full of houseplants or whatever, and aliens/zombies/genetically-engineered frog-bear hybrids/H1N1 flu/bird flu/Big-Bird Flu¹/whatever attacked Earth and killed everybody except for you, these are the plants that could maybe keep you going for a few more miserable weeks as you starved to death, dazed by grief and shock and completely alone. I think I personally would get the hell out of the botanical garden and set up in a nice abandoned supermarket somewhere, with a can opener, charcoal grill, and a few blow-up dolls or mannequins for company, but hey. It's your apocalypse; you do what you like.

Ananas comosus. (pineapple) Edible portion: ripe (!) fruit.

Cereus peruvianus. (Peruvian apple cactus) Edible portion: fruit, seeds.

Coffea arabica. (Coffee plant, coffee tree) Edible portion: flesh of berries, roasted seeds.

Cordyline fruticosa. (ti plant) Edible portion: rhizome, young leaves.

Eriobotrya japonica. (Loquat) Edible portion: fruits (excluding seeds).

Hylocereus sp. (dragon fruit cactus) Edible portion: fruits, seeds.

Monstera deliciosa. (Split-leaf philodendron) Edible portion: ripe (!) fruit.

Musa x 'Cheeka' and some other Musa cvv. (Banana, plantain) Edible portion: fruit, flower, trunk.

Myrtillocactus geometrizans (Whortleberry cactus) Edible portion: fruit.

Opuntia microdasys (Bunny ears; shown), and most other Opuntia species (Prickly pear). Edible portion: fruit, stems.
Of the above, the three I'd recommend would be Cereus peruvianus, Myrtillocactus geometrizans, and Coffea arabica. Cereus is definitely a pretty nice guy, and although I don't know Myrtillocactus as well, it seems friendly enough so far, and the fruit is supposed to resemble blueberries. Even if it's a long shot, that's still pretty cool. Also the color is nice -- the photo makes it look more green than blue, but in person it's more blue than green.

Coffea arabica is a weird one to recommend, since it's supposed to be a fairly difficult plant. Monstera deliciosa would be the more obvious choice for the third recommend. But, if I'm honest with myself, my Coffea has done better here than my Monsteras have. So Coffea it is.

The anti-recommend would be Opuntia microdasys, because of the glochids (tiny barbed hairs that get embedded in skin and itch and hurt -- they're terrible). I think Opuntia microdasys is actually the very species of Opuntia that traumatized me as a child in Evil Grandmother's house.

Not pictured:

NOTE: Much of the below information was gathered from Plants for a Future. I'm reaching kind of hard for plants that qualify, but everything in the below list is either a plant I've grown indoors more or less successfully, or a plant I've heard of people growing indoors more or less successfully. Additional suggestions are welcome.

•Abutilon cv. (Flowering maple) Edible portion: flowers. Leaves are technically edible but not very good.
•Agave americana, A. parryi, A. tequilana (Century plant, tequila agave) Edible portion: baked leaves, stem, and seeds; sap and fermented sap. Some people's skin is irritated by the sap. (Usually too large to be particularly good houseplants.)
•Aloe vera (Medicinal aloe) Edible portion: juice from center of leaves. Avoid juice from near the leaf surface if you like the current speed of your digestive system.
•Amaranthus caudatus (Love-lies-bleeding) Edible portion: leaves, seeds. (from comments; not common as houseplant)
•Aptenia cordifolia Edible portion: leaves. (from comments; uncommon as houseplant; likely harmful in large amounts)
•Araucaria araucana (Monkey-puzzle tree) Edible portion: seeds (fresh, cooked). (uncommon as houseplant)
•Araucaria bidwillii (Bunya-bunya) Edible portion: seeds (fresh, cooked, partly sprouted). (uncommon as houseplant)
•Asparagus setaceus (Asparagus fern) Edible portion: cooked young shoots. Apparently does not include the related A. sprengeri, though I'm not positive about that.
•Aucuba japonica (Spotted laurel, Japanese laurel) Edible portion: cooked leaves, but you'd have to be fairly desperate, from the sound of it.
•Calathea allouia (Sweet corn root) Edible portion: roots. (from comments; I've never actually heard of it being grown as a houseplant)
•Capsicum annuum and some other Capsicum spp. (Ornamental peppers, Sweet peppers) Edible portion: fruits.
•Some Caralluma spp. Edible portion: stems? I assume? Likely toxic in large quantity (from comments; uncommon as houseplant)
•Celosia argentea (Lagos spinach, Feather cockscomb) Edible portion: leaves. (from comments; I've never actually heard of anyone growing it as a houseplant)
•Chamaerops humilis (Dwarf fan palm) Edible portion: young leaf buds or suckers, fruit. (uncommon as houseplant)
•Citrus sinensis (Orange), C. limon (Lemon), other Citrus, Citrofortunella, and Fortunella spp. Edible portion: fruit, flowers.
•Dasylirion wheeleri and other Dasylirion spp. (Sotol) Edible portion: cooked or fermented stem, flowering stem. (I've seen it sold as a houseplant, but I don't know anyone who's actually grown it successfully indoors.)
•Ensete ventricosum (Ornamental banana?) Edible portion: rhizomes. (from comments)
•Epiphyllum anguligar Edible portion: fruits. (from comments)
•Some Ficus fruit, but not the species ordinarily cultivated indoors.
•Hibiscus rosa-sinensis (Tropical hibiscus) Edible portion: flowers, young leaves (?). Root is technically edible but not very good.
•Hydrocotyle leucocephala (Brazilian pennywort) Edible portion: leaves. (from comments; uncommon as houseplant but maybe semi-common as aquarium plant)
•Ipomoea batatas (Sweet potato) Edible portion: tuber. Uncommon as houseplant, though some ornamental varieties are widely grown outdoors.
•Laurus nobilis (Bay tree) Edible portion: leaves (fresh or dried), fruit, flowers.
•Liriope spicata (Lilyturf) Edible portion: cooked roots. (Rare as houseplant, though I'm growing the variety 'Cassidy' inside now. It's going so-so.)
•Maranta arudinacea (Arrowroot) Edible portion: tubers. (from comments; I've never actually heard of it being grown as a houseplant)
•Muehlenbeckia complexa (maidenhair vine) Edible portion: "fruit" (actually swollen flowers). (uncommon as houseplant but not unheard of)
•Ocimum basilicum (Basil) Edible portion: leaves.
•Olea europaea (Olive tree) Edible portion: fruit.
•Ophiopogon japonicus (Snake's beard) Edible portion: root. (Rare as houseplant, though I'm growing O. planiscapus var. nigrescens indoors now. It's not particularly satisfying: growth is slow.)
•Origanum majoranum (Marjoram) and O. vulgare (Oregano) Edible portion: leaves.
•Oxalis deppei (Iron cross oxalis) Edible portion: leaves, flowers, root. Excessive consumption can lead to calcium deficiency and other problems.
•Oxalis stricta (Yellow wood sorrel) As for O. deppei. It's a common enough hitchhiker in houseplants (around here, anyway) that I figure it qualifies as a houseplant, though it's rarely (never?) cultivated indoors on purpose.
•Oxalis triangularis (False shamrock, purple shamrock) As for O. deppei.
•Pachira aquatica (Money tree, Water chestnut, Malabar chestnut) Edible portion: nuts, leaves, flowers. (from comments)
•Passiflora spp. (Passion flower, Passion fruit) Edible portion: fruit. (from comments)
•Perilla frutescens (Perilla, Shiso, Beefsteak plant, Purple mint, Japanese basil) Edible portion: leaves. (from comments)
•Persea americana (Avocado) Edible portion: fruit.
•Portulacaria afra (Elephant bush, Spekboom) Edible portion: leaves.
•Rosmarinus officinalis (Rosemary) Edible portion: leaves. (I know people grow it indoors, but I don't recommend it.)
•Salvia elegans (Pineapple sage) Edible portion: leaves. (uncommon as houseplant, but undeservedly so)
•Salvia officinalis (Sage) Edible portion: leaves. Can be toxic when used to excess and/or over long periods.
•Saxifraga stolonifera (Strawberry begonia) Edible portion: leaves, flowering stem. Usually cooked.
•Sempervivum tectorum (Houseleek) but not necessarily other Sempervivum spp. Edible portion: young leaves and shoots. (much better as an outdoor plant than an indoor one, in my experience)
•Solanum lycopersicon (Tomato) Edible portion: fruit. (from comments; uncommon as houseplant)
•Stevia rebaudiana (Stevia) Edible portion: leaves.
•Thymus vulgaris (Thyme) Edible portion: leaves.
•Trachycarpus fortunei (Chusan palm, Chinese windmill palm) Edible portion: young flower buds (cooked).
•Tropaeolum majus (Nasturtium) Edible portion: leaves, flowers, seed, seedpod.
•many Yucca spp., including Y. guatemalensis, the only one commonly grown indoors. Edible portions: flowers, fruit, leaves, stems. (from comments)
•Zingiber officinale (Ginger) Edible portion: rhizome. (from comments; I'm told it's a fairly uncooperative houseplant)

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¹ ("Mr. Hooper's Revenge")

Recent new plants: Agave, Zamia, Pachycereus, Myrtillocactus

It's fairly normal for me to go through periods of buying the same kind of plant, or sometimes even multiple copies of the exact same plant, and then realize that I was doing this only somewhat later. Most of my orchids all arrived at about the same time, for example, as did most of my African violets (which also all left at about the same time, too: African violets are social plants, and travel in swarms).

Lately I seem to be having a cactus period: in addition to the Astrophytum ornatum I mentioned a while ago, I've also gotten a couple other cacti recently, plus an Agave which, though not a cactus, shares enough characteristics with cacti that I think we can include it as an honorary cactus for these purposes.

Myrtillocactus geometrizans ("whortleberry cactus"). Or at least that's how Lowe's had it marked. I blame Cactus Blog for this one: they'd posted about Myrtillocactus a couple times in the days before I bought this (mid-August). I'm not positive, but I think the cost was something like $4 or $5.
UPDATE: I now believe this is probably not a Myrtillocactus after all, but a Stenocereus pruinosus. This is based on their respective photos at cactiguide.com.

Pachycereus marginatus, I think. I'd wanted one for a while, but it took me until mid-October to remember that there were some at the ex-job. Not positive on the ID, but hopeful. It cost about $5.
UPDATE: I now believe this is an Isolatocereus dumortieri. Which I am okay with.

Zamia furfuracea? It's a very young Zamia ("cardboard palm" -- though it is neither), anyway. From a hardware store in Iowa City. We'd had these at work before, as much larger, less full plants, and they stayed around for over a year without selling. Then they suddenly all got scale of some kind and we threw them out. (It was more like seven out of eight got scale, and we couldn't be positive about the eighth.) I would have bought one way earlier, but for size and price. This was very reasonable ($6-7?), and only in a four-inch pot, so it got to come home with me about three weeks ago.

Agave 'Blue Glow.' Speaking of getting things in that then don't sell, I suspect Wallace's, in Bettendorf, is feeling this a little. They have a lot of fairly cool Agaves there in four-inch pots, which I think they got in in the spring for people to use in succulent plantings outside. They still have a lot of them left as of Halloween, when I bought this. 'Blue Glow' is supposed to be a hybrid of A. ocahui and A. attenuata. Leaves are a very cool blue-green, and have yellow and red spines on the leaf edges which are easier to see in the full-size picture. This was also about $6, and the plant had offset, so I got two plants out of it.