Fall Over Foliage

Just fancy tropical plants

by Jay Vannini

*Piptospatha* (*Kiewia*) *ridleyi*. ©J. Vannini 2021

Rare and unusually colored tropical foliage plants have attracted a sizeable global following over the past decade. Many talented young plant collectors have graduated from tabletop succulents and other common potted ornamentals and onto offbeat rainforest origin gems to adorn their living spaces and greenhouses. In doing so, they have tested the boundaries of home cultivation and bulldozed conventional perceptions as to what decorative “houseplants” can be in the 21st century. The popularity of novelty tropical foliage is evident almost everywhere on the internet as well as in glossy print media that caters to the home & garden smart set.

The two major regions from whence these plants originate are Central America-northern South America and Southeast Asia-Malesia. Many former rarities known only from niche market mail order nurseries are now familiar plants offered by many well-stocked plant shops and garden centers. These include bromeliads, dieffenbachias, aglaonemas, hoyas, ferns, begonias, gesneriads, dracaenas, marantas, calatheas and peperomias. Increased commercial interest from buyers living in the northern countries prompted export-focused nurseries located in these two regions to greatly expand their offerings of ornamental foliage to include poorly known, newly discovered and recently published, or even undescribed plant species. These exporters, together with domestic specialty nurseries, are now ubiquitous features at tropical plant shows in the U.S. and the EU.

Growing numbers of plant people concentrate their efforts on collecting certain families or genera that include high numbers of showy species and hybrids suitable for cultivation in modern interiors of northern countries. Once considered rather boring wards of teetotaler gray-haired ladies, the incredible diversity of jewel box type begonias–one of largest plant genera–that have been discovered in tropical Asia over the past 15 years has attracted an enthusiastic new following. Likewise, compact species of aroids with heavily marked or attractively textured leaves are also a popular and very visible subset of this hobby. Stem succulent mania, while off from its frenzied highs of a few years back, still generates enough demand to drive clearly unsustainable levels of wild collection of some in-vogue groups such as globular cacti, dudleyas, rare euphorbias and conophytums across the Americas, Madagascar, and southern Africa.

Maintaining a large collection of any type of living organism in top form is very time-consuming and can sometimes, inexorably, skirt perilously close to morphing into a chore. I am quite fortunate in being able to work at my own pace at my home as well as in a large, climate-controlled commercial greenhouse environment. Given this freedom, I try and spend several hours a day working with my plant collection, not for my plant collection.

My whispered guidance to newly minted plant collectors is that if you are finding yourself constantly inconvenienced by having to care for your charges and see a general decline in the health of your treasured pets, perhaps you have a few too many high maintenance plants in your life?

I know, I know.

Hard to believe, right? Too many plants? Is such a thing even possible?

As fall 2021 draws to a close, the following showcases a couple dozen choice selections with interesting leaves that caught my eye of late. Some exhibit disruptive color patterns that serve to hide them from leaf predators and add to their interest as decorative items for humans. More than a few also have beautiful flowers. These plants were plucked from my personal collection for the test photographs that fill out this article. I have added short notes on their cultivation, availability and taxonomy. All can be grown to full maturity in 12”/30 cm containers. Many are readily available from plant sellers on the internet at comparatively modest prices; others remain firmly in the purview of specialists and may be tough or nigh-impossible to find for sale online.

All plants and images shown here are mine. Five exceptions aside, these photos were taken this past week with a Nikon DSLR fitted with a Nissin ring flash.

So, on to celebrating color and form in “The UnSalad”.

Gallery

Echeveria laui (Crassulaceae) – Oaxaca State, México

Discovered in a remote area of Oaxaca in 1974 by expatriate plantsman Alfred Lau and published a couple years later, this wonderful chalk white to alabaster colored epipetric succulent has recently become reasonably common in cultivation from seed and PTC propagated stock. It is slow growing and greatly resents constantly shaded conditions and wet feet. Extreme care is required when overhead watering as well as during repotting so as not to mar the glaucous blush on the leaves that makes this and E. cante such irresistible xerophytes. Powdered, water soluble fertilizers designed for foliar or drench feeding will stain leaves so I recommend using prilled, time release ferts instead. The rosette shown in the image above was recently transplanted and has had some of the very fine protective bloom scuffed from its leaves despite great care being taken (but see my fingerprints on several leaf edges nonetheless) to avoid just this. Leaf surface perfection returns only after many months, even when grown in very dry and bright locations, so mind your fingertips when moving these plants!

Mostly very slow to offset but can, with persistence, be propagated from single mature leaf pulls.

Agave albopilosa ‘Lolita’ (Asparagaceae) – La Huasteca Canyon, Monterey, Nuevo León State, México

Despite rumors of a very different-looking Agave striata-like century plant hiding on high cliffs in the Cumbres de Monterey Biosphere Reserve that date back almost four decades, this unique, tufted leaf species was formally described as recently as 2007. By the time of its formal publication succulent poachers had, according to many informed accounts, already removed most plants accessible to amateur rock climbers within parts of El Cañón de La Huasteca. Not coincidentally, some larger specimens also appeared soon after its discovery on the tables and in the gardens of a few well-known U.S., European and Japanese plant collectors. Despite the likelihood at least one or two have bloomed in southern California and/or Texas I am not aware of any flowering events reported in captivity yet. Wild-collected seed flooded the market beginning in 2010 and remains available from online vendors in the EU from time to time. This IUCN Critically Endangered species was put into PTC by a well-known southern California nursery early in the last decade, but the resulting clonal propagates I have seen ended up malformed, clustering disasters. Because of this, many better known succulent nurseries have once again focused on seed-grown material that, of necessity, continues to be collected from flower stalks of mature individuals in La Huasteca.

Shown above is a seed grown clone of mine that I selected early on and christened ‘Lolita’ for its precocity, since most A. albopilosa seedlings grow at what seems a near glacial pace. This individual is almost perfectly globular in aspect and has grown to near flowering size (~16”/40 cm diameter) in a bit over nine years from seed sow. Grown on my rear deck fully exposed to the sky in coastal northern California. Out of curiosity I tested its genetics but–to my surprise–it came up with the same genome size as a “normal” (i.e., slow-growing) example of this species. It seems likely that karyotyping will be required to determine whether or not this exceptional individual is indeed polyploid. Unlike most seed-grown A. albopilosa I have handled and seen, this clone offsets reliably, albeit very sparingly, when young. By carefully shepherding these staggered divisions I have able to propagate several generations of different sized offsets over the past five years by harvesting “grass pups” as soon as they are safe to remove from the parent stock.

Aloe castilloniae (Asphodelaceae) - Plateau Mahafaly, Madagascar

One of the most appealing dwarf aloe species, this soft thorn-studded and colorful plant is justifiably popular with tabletop succulent collectors. Discovered and published in 2006, the plant rapidly found its way into cultivation via accessions made by visiting botanists and commercial plantsmen. Believed to be restricted to a small coastal range in Madagascar’s far south. Now widely grown from seed and rooted offsets, I have found it fast growing once it is solidly established. A great subject for cultivation in terracotta bulb pans and bowls. Its medusoid habit and sprawling to pendent stems more than 40”/1.0 m long and very colorful flowers on short inflorescences make large, specimen sized plants real prizes for their owners.

Widely hybridized–especially over the past several years–so prospective buyers should ascertain that their acquisition is indeed the true species and not a hybrid if they are looking for the leaf characters shown above.

Below, a late 2018 vintage complex hybrid of my own using Aloe castilloniae as the pollen parent. This particular selection (‘Vampyre Squid’) exhibits very strong influence from that species in terms of form as well as inflorescence color and remains fully dwarfed. Maternal dominance is common in A. castilloniae hybrids, but definitely not in this one where the pollen parent stands out. Shown fully mature, clambering out of a 4”/10 cm pot for size reference.

Bulbophyllum reticulatum (Orchidaceae) - East Kalimantan, Indonesia

Epiphytic orchids, outside of the pleurothallids, a couple maxillarias and a handful of Malesian Phalaenopsis species, rarely have distinctive markings on their leaves other than colored mid-veins. This highly desirable if somewhat tricky to grow epipetric to epiphytic tropical Asian species is famous for its vividly contrast veined leaves. Flowers are fragrant and somewhat showy.

Pelexia cf. laxa (Orchidaceae) - Leaf form from Ecuador and Perú

This fairly common terrestrial orchid species occurs throughout the Neotropics but is typically a rather unremarkable looking plant in most areas. Some populations in Ecuador and Perú have extremely handsome foliage that ranges from glossy black to these heavy spotted clones and are very popular with jewel orchid collectors.

Nephelaphyllum pulchrum (Orchidaceae) – Peninsular Malaysia and throughout Malesia

A curiously colored but extremely handsome leaf litter mimic from tropical forest understories throughout its range. Another of the larger jewel orchids that has haltingly made its way into PTC in the northern countries, although seed grown nursery grown stock imported from Asian sources appear to be easier to grow and flower.

Dieffenbachia sp. (Araceae) – Undisclosed locality, Panamá

A recently discovered (early 2019) compact and seemingly localized species from Panamanian lowland tropical rainforest that has seen very limited commercial distribution among specialist collectors over the past couple years. This outstanding terrestrial ornamental aroid is remarkable for both its attractive leaf color and distinctly velvety aspect; the latter feature one that is extremely rare in the genus. In some ways, it seems a much better version overall of the very popular contemporary mass market hybrid, Dieffenbachia ‘Reflector’. The two clones that I own are rather slow growing for a Dieffenbachia species but are certainly worth the time and effort required to grow to specimen size.

A very desirable plant all round.

Southern Central America has a wide variety of beautiful *Dieffenbachia* species. This is a very showy *D. cf. tonduzii* photographed in nature in the Caribbean lowlands of western Panamá. Author’s image.

Dieffenbachia sp. (Araceae) – Leoncio Prado Province, Perú

Another recent discovery that is one of the more attractive dumb cane species to make it into cultivation of late, and that’s with the knowledge that there are some very beautiful wild dieffenbachias in southern Central America! Handsome, reasonably large, and effortless to grow, it is a stunning new foliage entry that eclipses many older horticultural hybrids that favored high-white foliage.

Adelonema pallidinervium (Araceae) – Orellana Province, Ecuador

Originally published as Adelonema pallidinervia in 2016, the specific epithet has since been modified to reflect the correct termination. A Neotropical aroid genus that has several beautiful species (e.g., A. wallisii) formerly included in the Old World Homalomena (see below). When grown under very shady, warm and humid conditions, as shown here the upper leaf surfaces can exhibit a satin-subvelvety aspect on older leaves of this very compact species.

Homalomena sp. (Araceae) - Tapanuli, North Sumatra, Indonesia

Many of the so-called “sandstone” homalomenas from different localities in Borneo have made it to cultivation over the past two decades. Most have attractive greenish-brown, cocoa brown or copper colored foliage with subvelvety to velvety leaf textures. Many of the more common forms have obovate leaves and remain compact in cultivation. This very showy species that was collected in North Sumatra has lanceolate leaves that are dark, velvety brown above with red lower leaf surfaces and emergent foliage. My Malesian aroid collection is mostly comprised of rheophytic species from across Borneo, but this Sumatran terrestrial is an outstanding and surprisingly robust pot plant under warm greenhouse conditions.

This plant as a very good example of parallel evolution in the leaf morphologies of understory terrestrial Malesian and Neotropical rainforest aroids with dark, velute foliage and red or violet abaxial leaf surfaces.

Piptospatha (Kiewia) ridleyi (Araceae) – Southern Thailand through Peninsular and Sarawak, Malaysia

One of the smaller Malesian rheophytic aroids that I grow and mentioned above, this late 19th century find is a long-time favorite of the aquarium trade and has also found a more recent following among terrarium growers. As is shown in the image at the top of the article, this species also grows well as an emersed subject in warm, humid greenhouses. I acclimated a pair of severely dinged starts sold to me as immersed plants for a couple months in a cloched flood tray before moving to grow fully exposed on a shady greenhouse bench. A gorgeous southeast Asian rainforest aroid with plenty of desirable “camo” colors evident in this clone (some are uniformly green). One drawback to growing this species on an open bench is that the leaves will reliably (and permanently) bleach at light levels exceeding about 300 fc/3200 lux (see a few pale leaves above).

The subglobular, nodding inflorescences that resemble caped supplicants are an added attraction.

Mapania enodis (Cyperaceae) – Peninsular Malaysia, South Sumatra and Central Kalimantan, Indonesia

One of the best metallic blue plants in commerce (flash helps), this widespread tropical sedge is often sold misidentified as M. caudata. There are now a variety of distinctive clones now in cultivation in the U.S. and the EU with differing leaf dimensions that originated from Thai plant sellers in the late 2000s on into the late 2010s.

Mapania sp. (Cyperaceae) – Tambunan District, Sarawak, Malaysia

A very showy and rather aberrant hemiepiphytic sedge with whorled leaves and corkscrewed stems that mimic some sympatric Malesian screwpines (Pandanaceae). This handsome species has chromium silver leaves as seedlings and pale bluish-gray metallic faced foliage when larger. Marginal spines on the leaves are soft and inoffensive and it seems an easy plant to grow once acclimated. A succulent-stemmed climber, so durable totems are a must. I have two very similar looking near mature clones originating from different localities in Sabah and northern Sarawak State, one of which is now over 40”/1.0 m tall, so it seems a good candidate for domestic production from seed sometime in 2022.

Begonia cleopatrae (Begoniaceae) – Cleopatra’s Needle Range, Palawan, Philippines

One of many microendemic Asian begonias with beautifully marked foliage being sold in northern markets over the past decade. Impossible not to fall in love with if you like fancy jewel box type begonias with thick leaves. Published in 2010, one of my personal favorites in a megadiverse genus with hundreds of candidates for best-looking species.

Begonia ignita (Begoniaceae) – Native range unknown but believed to be endemic to Sulawesi, Indonesia

One of Chei-Wei Lin et al. many remarkable ornamental begonia finds from Malesia over the past decade. Described from a cultivated plant in Bogor Botanical Gardens and published in 2017, this very showy, orange flowered species had found its way into western cultivation from an unknown locality some years earlier. A remarkable begonia that combines very attractive foliage with showy, vividly colored flowers and petioles.

Begonia kui (Begoniaceae) – Native range unknown but believed to be endemic to Thai Nguyen Province, northeastern Vietnam

Yet another highly ornamental Asian begonia described from a cultivated material discovered in a floral shop in Taiwan and published in 2007. Leaves on well cultivated plants are long-lived and dinner plate sized. Smaller plants grow well in pots, but I grow specimen material in large bulb pans, as shown in image above, staged in a 10”/25 cm container.

This species is sporadically available from mainstream foliage suppliers in the U.S.

Goeppertia sp. (Marantaceae) – Napo Province, Ecuador

Goeppertias are a major carve out (Borschsenius et al., 2012) from the more familiar arrowroot (Marantaceae) genus Calathea. It is a large and species-diverse genus that almost suffers a surfeit of riches, with dozens of species and cultivars sharing exceptional looks and relative ease of cultivation. Many of more desirable forms originate from lower elevations along the eastern slopes of the Andes in northwestern South America discontinuously into southeastern Brazil. Many very handsome select forms are now commonly available from mainstream tropical foliage nurseries out of PTC and are popular subjects as pot plants, as ground cover for interiorscapes, and in vertical plantings.

Aficionados should take note that many of the smaller ornamental Goeppertia species will consistently brown tip when irrigated with fluoridated tap water (usually injected at ~1 ppm by water companies), so periodic flushes with pure water are useful in producing and maintaining leaf perfect plants.

This particular accession proved very delicate during the establishment phase from freshly wild-collected stems, but now works well in a basket filled with well-drained substrate having some organic matter incorporated. In some ways, it looks more like an aberrant Maranta species than a Goeppertia. One of my all-time favorite tropical foliage plants in this size range. With electric green, glittering leaves bearing a strong superficial resemblance to the plumage of male resplendent quetzals (Pharomachrus mocinno) this apparently undescribed species originated from a field collection of a handful of specimens made by a commercial source in Amazonian Ecuador in 2019. It was originally misidentified by the collector as a local form of the widespread G. zebrina (!!), but its close affinities are unclear.

Despite best efforts, photos others and me have taken of them this year do not do living plants justice. Grown in the deep, dappled shade of a warm tropical greenhouse, the herringbone pattern, satin-surfaced leaves reflect incident light in a unique way that is quite appealing.

Goeppertia dressleri (Marantaceae) – eastern Panamá on into the western Chocó Province, Colombia

A very beautiful species from lowland rainforests on both slopes of eastern Panamá and on into coastal Chocoan pluvial forests in extreme western Colombia. A handsome arrowroot with subvelvety leaves closely associated with deep shade and red clay soils in nature, the plant is a low growing gem that often has vivid red midveins. This is a leaf on an immature plant that is just starting to show a hint of future promise.

Uncommon in cultivation compared to many other well known members of the genus.

Another young plant shown growing in nature in lowland rainforest understory on exposed, lateric soils in Panamá Province, Panamá.

Labisia pumila “Pink Edge” (Primulaceae) – Throughout Malaysia, insular Indonesia, and New Guinea

A variable and very commonly cultivated tropical primrose that is sometimes sold under a junior synonym (L. pothoina). This is one of the higher color forms popular with collectors that I grew from seed provided by Chris Hall and Arden Dearden in Queensland, Australia. This species is widely used in traditional medicine in Asia for treating a variety of ailments, despite some question as to its efficacy.

Ardisia sp. aff. obovatifolia (Primulaceae) – Native range unknown but likely East or North Kalimantan, Indonesia

A blizzard of rainforest understory primroses from across Borneo started hitting the rare plant market about five years ago, often piggybacked with enigmatic aquatic and rheophytic aroids exported by intermediaries as unrooted stem cuttings from Djakarta, Singapore and Bangkok. Some of the Ardisia species that have appeared on the market are likely juvenile forms of arborescent species and may bear little resemblance to an adult shrub; others appear to remain dwarfed into maturity (C.W. Lin, pers. comm.). This species is, to my eye, one of the more attractive pebbled-leaf lowland rainforest primrose species currently available in northern countries, sometimes marketed as A. “Dino”.

Danaea sp. (Marattiaceae) – Veraguas Province, Panamá

Danaea is an uncommonly cultivated, medium-sized genus of Neotropical ferns that, together with the better-known genus Angiopteris, are part of the Marattiaceae. Until recently, some respected fern specialists claimed that it was impossible to succeed with dwarf members of this genus in cultivation for more than a year or so.

This is one of a half dozen plus rhizome grown danaeas I grow that are all thriving after three years plus in my hands. Always take care when listening to so-called experts who clearly don’t know what they don’t know.

Most Central American and Panamanian danaeas are very compact, leathery leafed ferns that often occur near or in streambeds. At least three of them have metallic greenish-blue or blue leaves when conditions are optimal. While these lovely ferns are admittedly very challenging to establish from small rhizome sections, they can be surprisingly fast growing once fully acclimated. Note that these are delicate ferns best suited for advanced growers with very humid, temperature controlled environments. Mineral substrates, flood trays, deep shade (<250 fc/), light fertilization and pure water in large quantities are key to success with the smaller terrestrial species in this genus.

Neolepisorus ovatus (Polypodiaceae) – Southern China, Myanmar and Vietnam

A very widespread ornamental terrestrial fern with drop-dead good looks that is variable in both leaf form and color across its range. Much has been made in the past of the color and form differences between specimens that originated in southern China and northern Vietnam. A quick look at recent material that has been collected in China and sold in the U.S. indicates that these differences may be more individual rather than locality linked. I grow several clones said to have originated from both countries and find them all easy once established.

A well grown, high color specimen is a guaranteed traffic-stopper. This species is now readily available in smaller sizes from some online nurseries in the U.S.

Impatiens morsei (Balsaminaceae) – Southeastern China

One of the most spectacular members of a genus that is very popular in ornamental horticulture, this medium sized Chinese balsam also has large, shell-like and very showy corollas. There is some question as to whether the plants in cultivation accurately represent wild forms of the species or have been greatly improved by selective breeding. Whether wild or line-bred, this is a very beautiful plant to have around.

Impatiens sp. (Balsaminaceae) – Southwestern Uganda and adjacent eastern Republic of Congo

A stunning central Africa parrot beak impatiens that has been in cultivation as I. bombycina (sp. ined.) for a number of years. The lustrous greenish black leaves with hints of blue iridescence and curiously-shaped, colorful reddish-violet corollas make for a striking combination when the plant is in flower. A cool grower that requires lots of shade and water to thrive and apparently languishes when exposed to prolonged heat spells.