Project Description

Sun Pitcher Plant – Heliamphora

The Sun Pitcher Plant (Heliamphora) is an exotic pitcher plant growing among the clouds of South America. A relative of the North American Sarracenia and Darlingtonia californica, the pitfall traps turn solid hues of green, red, and dark purple. They employ many of the same tactics as other pitcher plants – a “pitfall” trap with slick surfaces, sweet nectar trails, and sharp downward-facing hairs to prevent insect escape – but in a streamlined appearance as compared to its cousins. Unique physiological characteristics include thicker, squat pitchers, a nectar spoon above the trap’s opening, and beautiful white-pink flowers that lack petals.

In the last few decades, numerous additional Heliamphora species were discovered bringing the total to 23 – more than the species of Sarracenia in North America.

Biology of a Sun Pitcher Plant

The trap

The Sun Pitcher uses many of the same tactics as other pitcher plants, – a “pitfall” trap including the slippery lip, sweet nectar trails up and down the pitcher to lure crawling insects, and sharp downward facing hairs which both lead bugs into the trap and prevent their escape.  The Sun Pitcher, however, has evolved further to refine its trapping mechanism. 

Unlike other pitcher plants, the hood of the Sun Pitcher is more of a tiny cap, does not protect the pitcher from rain, or provide a particularly robust landing platform for flying insects. This structure is commonly referred to as a nectar spoon (mmm, sounds delicious!), and because of its concave shape and glands, secrets and holds a dense glob of insect-luring nectar. The diminutive size of the cap may actually be an advantageous evolutionary adaptation over larger pitcher plant hoods, as Adrian Slack observed that no more than one flying insect could land on it at a time. Insect brawls break out as they fight for a spot to sip at the nectar. Pushing and shoving insects are more susceptible to fall into the trap below.

If not for the protective hood, pitchers on other kinds of pitcher plants would fill with rainwater, tip over from weight, and be rendered useless at catching bugs. However, the Sun Pitcher uses rainwater to its advantage.  The traps on the Sun Pitcher plant naturally grow an open slit, or pore midway up the seam of the trap, which acts as an overfill fail-safe, ensuring that the pitcher doesn’t become flooded with water.  Actually, the open slit lets just enough water escape to maximize the efficiency of the trap.

The trap rigidity is adapted to higher winds that would otherwise topple Sarracenia pitchers.

Sun Pitcher plants produce no digestive enzymes of their own (none have yet  to be discovered). Instead, they leverage bacteria which inhabit the rainwater within the pitchers and breakdown prey into nutrients that are absorbed by the plant.

Frogs are commonly found relaxing in Heliamphora pitchers, ogling a nectar spoon above, waiting for unwitting insects to buzz by. The frogs aren’t Sun pitcher food themselves, but their feces are! The pitcher literally spoon-feeds the happy frogs, and the frogs pre-digest food for the pitcher which lacks robust digestive enzymes. While this may sound gross, the high nitrogen content in feces acts as a great nutrient source for Heliamphora.

Lizards and carnivorous insects have also been noticed hanging out around the plants, snagging insects attracted by the nectar, and dropping feces into the pitchers.

Sub-soil biology & requirements

Heliamphora grow on mountaintops with daytime temperatures between 60-72 degrees and nighttime temperatures between 45-50 degrees Fahrenheit. Dips near-freezing are not uncommon. They are considered highland tropicals and will survive extreme lows down to 35 degrees and highs up to 90 degrees Fahrenheit. Frequent rainstorms are fueled by condensing clouds as they rise up the sides of the mountains, keep Heliamphora pitchers filled, and humidity high. Stormy winds are common, so good air circulation is a must.

With time, healthy Heliamphora produce offshoots that grow into beautiful plant clumps that can be divided into new plants.

Flowers

Heliamphora flowers are beautiful and emerge from the plant on tall, red stems during winter and spring. They open progressively along the length of the stem and require cross-pollination with a special technique.

The bell-shaped flowers have no petals, but rather showy tepals (a structure somewhere in-between petals and sepals) that change from white to pinkish and pale green as they age.

Stigmas and anthers mature at different times to encourage cross-pollination with other blooming Heliamphora. When a flower opens, the greenish-white female stigma is immediately receptive for only a few days. However, the cluster of tube-like male pollen sacks (anthers) do not produce mature pollen until after the stigma looses receptivity (it’ll turn brown when no longer receptive). This means you’ll need to cross-pollinate flowers if seed is your goal.

Heliamphora pollination is tricky, and best done naturally by the vibrating wings of bees and flying pollinators. This isn’t always an option for indoor growers, so a simple technique using a tuning fork can mimic the vibrations that cause pollen release. For this method, acquire a small tuning fork, grab a smooth piece of paper, and a small paintbrush.

Place the piece of paper below the flower and touch the pollen sacs with a vibrating tuning fork. If pollen sacs are mature, a small amount of yellow dust-like pollen will fall to the piece of paper. Collect the pollen with a paintbrush and paint it onto the receptive stigma of another recently-opened flower.

You can also easily hybridize Heliamphora by cross-pollinating different species. Simply collect pollen from one species and apply to the stigma of another. Some common crosses include H. nutans x heterodoxa, H. heterodoxa x minor, and H. nutans x minor. Hybrids will have a mix of characteristics from each parent and extra vigor.

Successful pollination will result in seed production within 2-to-four months. The ovary will swell, turn brown, and crack open releasing seed. No stratification is needed and seeds can be germinated immediately. For more details on Sun Pitcher seed germination, check out the section below.

History of the Sun Pitcher

 

Heliamphora nutans was first found in 1838 by the German naturalist R.H. Schmoburgk atop Mr. Roraima. In 1840, G. Bentham named the plant for the Greek words helos, meaning marsh, and amphora, meaning pitcher or vessel – an appropriate name for this variety of pitcher plant. However, the similarity with the word helios, meaning sun, stuck Sun pitcher plants with their common name.

About a century later, a second species was discovered, followed by more discoveries in the 1950s and 1970s. The use of helicopters to explore the tepuis mountaintops made expeditions and discovery more common. Leading the charge were several European naturalists and scientists – Joachim Nerz, Stewart McPherson, Andreas Wistuba, Andreas Fleischman, Peter Harbarth, and Thomas Carrow – who both discovered brand new species and corrected previously miscategorized ones. We now know there are at least 23 species of Sun pitcher plants with more discoveries expected.

Where to find Sun Pitchers in the wild

 

Sun pitcher plants are found atop the tepui mountains of the Guayana Highlands peak in southern Venezuela and northern Brazil. It’s a magical area 6,000-8,000 feet above sea level, rising even above the clouds themselves.

 Heliamphora cultivation, growing techniques & propagation

Heliamphora grow in nutrient-poor soils, but are accepting of numerous types of well-drained but wet soils. Try one part perlite, one part lava rock, and three parts long-fibered New Zealand sphagnum moss. Or, go crazy, and try 50% sphagnum peat moss and the remaining 50% an equal combo of pumice, perlite, lava rock, and fine orchid bark.

Four to eight inch (10-20 cm), drained plastic pots or glazed ceramics are ideal for a single mature Heliamphora. You may want to set these pots in shallow water saucers to maintain soil moisture.

Use distilled or reverse osmosis water. This can be inexpensively purchased in most grocery stores, or you can invest in a reverse osmosis (RO) filtration system that hooks up to a sink (bonus – this also provides great drinking water for humans and pets). If you’re watering daily, no water tray is needed. Otherwise, keep plants in a shallow water tray and water soil overhead, until water fills the tray. Soil should be kept permanently wet.

Heliamphora enjoy bright light. Brighter conditions will promote deeper pitcher coloration, genotype-permitting. Just make sure to avoid overheating pots and roots.

For indoor plants, Sun Pitcher plants will happily eat any bug that reasonably fits in a pitcher – from flies to mealworms. If feeding live insects isn’t your thing, you can use moistened, dried insects that can be found at pet food stores (lizard food).

Sun pitchers enjoy a good foliar fertilizer once or twice a month. Foliar feeding will promote faster pitcher growth and regular flowering.

Transplant Heliamphora in late winter or early spring. While the plants are uprooted, soak the roots in a vitamin B1 solution to reduce the stress of transplantation. While the pitchers a sturdy in the face of winds, they can be brittle – so be gentle.

Healthy Sun pitcher plants cluster into mounds of insect-devouring pitchers. Individual growth points can be divided during transplantation to encourage even more new growth.

Wash the roots of an uprooted plant so that you can visually identify individual growth points. As long as these growth points have a few supporting roots, you can break or cut them away from the parent plant. Soak both parent and new Heliamphora divisions in vitamin B1 to reduce stress on the plants and repot.

To supercharge recovery, mist your Sun pitchers with a foliar fertilizer two weeks later and remove any flower stalk that could exhaust the plants.

The physiology of Sun pitcher plants does not lend itself to cuttings. Use divisions and seeds for propagation.

See the flower section, above, for the unique flower fertilization technique used to produce seed from a Heliamphora. Once you have this seed, you can plant it immediately without need for stratification. Lightly spread the seed across milled sphagnum moss or the preferred soil. Use a seed tray and humidity dome to maintain high humidity, and keep conditions bright. Germination will occur in several weeks and several years later, you’ll have mature Heliamphora.

Hybrid Heliamphora will have characteristics of both parent plants, and the usual vigor that comes with a diverse gene pool.

Sterilized seed lends itself nicely to in vitro tissue culture of Heliamphora. Successful tissue culture introduction has made Sun pitchers much more common and affordable in recent years.

Keep air circulating to avoid fungus problems. In any case, avoid copper-based fungicides as they will kill a Sun pitcher plant. Scale will rarely attack Heliamphora and can be treated with an insecticide.

As previously mentioned, Heliamphora mostly require highland tropical conditions with temperature between 45 degrees and 75 degrees Fahrenheit. Extremes of 35 degrees to 90 degrees are tolerated, but not ideal. Keep air circulating with fans, and conditions humid.

Probably not great outdoor plants unless you live in highland tropics.

Great performers in warm and cool greenhouses, especially when frequently misted and grown near swamp coolers. Allow temperatures at night to drop, and keep things under 85 degrees Fahrenheit during the day.

Great candidates for well-circulated, cool terrariums. Use LED or florescent grow lights to keep temperatures low (and to be energy efficient!). Keep your terrariums in a cool spot, mist the plants often, and use ice packs at night to drop temperatures, if needed.

Sun pitcher plants need high humidity, cool average temperatures, and ample sunlight. These requirements make them poor candidates for windowsill growing.

Temperamental when conditions don’t meet highland tropical standards, Heliamphora aren’t great candidates for most bog gardens.

Sun Pitcher Plant varieties, subspecies & hybrids