Heliamphora

HISTORY

R. H. Schomburgk, a German naturalist, discovered these plants in 1839, while surveying the Guayana Highlands for The Geographical Society of London. G. Bentham, in 1840, established the genus on the basis of specimens collected by Schomburgk on Mount Roriama, which he named Heliamphora nutans.

The genus name is derived from two Greek words meaning "marsh" and "vessel." Since the prefix heli, also refers to the sun, the name has been interpreted to mean sun pitcher. The common names for Heliamphora are South American Pitcher Plant, Sun Pitcher Plant, and the Marsh Pitcher Plant, with the latter being preferred.

NATURAL HABITAT

Heliamphora are native to and grow only on the summits of the "tepui" or mesas of the Guayana Highlands of southern Venezuela, Guayana, and northern Brazil. The mesas are very high 5,000-10,000 ft. (1,524 to 3,048 m), flat-topped features isolated from one another by deep valleys with steep walls. One of the largest mesas called Auyan-tepui has an area of 286 sq. miles (750 sq. km.). Angel Waterfalls, the highest in the world, plummets 3,300 ft. (1,006 m) down the sheer wall of Auyan-tepui. The "tepui" form islands of vegetation which are adapted to much lower temperatures than the tropical jungles at their bases. The Guayana Highlands have an extremely high annual rainfall, often exceeding 100 in. (254 cm). The mesas are often shrouded by clouds and mist which keeps the humidity high. Weathering and erosion have carved valleys and canyons on the mesa tops and walls. The plateaus are remote and extremely difficult to reach, therefore, few people have seen Heliamphora plants growing in their native habitat.

So isolated is the area that it was almost 100 years after the discovery of the first species before others were found. The plants are confined to the top of sheer-sided mesas where they grow in acid soils in swampy savannahs exposed to the brilliant equatorial sun.

DESCRIPTION OF PLANTS

Heliamphora are herbaceous plants consisting of rhizomes from which arise simple, branched or dendroid stems. Both ensiform (phyllodia) and ascidiform leaves are produced and occur in rosettes in some species. Flowers which may be green, white or pink are borne on scapes that are longer than the leaves. (Fig. 3-25)

Leaves

The pitchers are roughly cone-shaped and in some species there is a constriction, of varying degree, which produces a bulging region below it with a flare-out above it, called the bell. The leaves appear to have been produced by rolling the sides of the lamina around a thin funnel and then securing the structure down the front along the leaf margins, leaving an external seam allowance that flares out forming two "keel-like" wings or ala.

The margins are either fused along their entire connective length or only in the lower region of the pitcher leaving a slit partway down the front of the pitcher. The slit maintains a constant level of water in those pitchers that do not have a pore below the slit, acting as an overflow for the water but not an escape hatch for insects. Some pitchers also have a pore which is located further down the front of the pitcher keeping the water level even lower.

A prominent midrib extends the length of the back of the pitchers. At the apex of the

Pitcher Plant Roots
Fig. 3-25 Heliamphora plant, including rhizome with roots, pitchers and flower stalk with flowers.

pitcher, in most species, is a hood, a spoon-like structure, with the concave surface facing into the hollow leaf. Glands and V-shaped hairs are located on the outer surface of the pitchers. In cultivation leaves are usually green, but with a hint of reddish coloration when grown in strong light.

Flowers

Several flowers are borne in a racemose inflorescence held above the leaves by a long peduncle. The ovary is densely pubescent and the glabrous stigma and style are surrounded by 10 or more stamens. The perianth is composed of 1 whorl of petal-like appendages, usually 4 in number, but occasionally 5-6. Flower color is not the same in all species and varies from shades of green, to pink or white with color darkening sometimes to deep maroon during fruiting. (Fig. 3-26)

TRAPPING

In most species the inside of the pitcher is zoned similarly to the ascidiform leaves found in most pitcher plants. The hood, when present, is plentifully strewn with nectar glands. Just below it, in the region of the opening and below, are numerous long, flexible, downward pointing hairs intermingled with nectar glands. This region attracts insects, offering them an unstable foothold. The next lower region is distinguished by smooth pitcher walls which prevent insects from maintaining a foothold. The walls of the lowermost region of the pitcher have sharp, stout, downward pointing hairs that prevent the upward movement of prey. (Fig. 3-27) Digestion, according to current knowledge, is due to bacterial activity in the watery bath that is maintained within the pitcher in nature by heavy rainfalls.

SPECIES OF THE GENUS HELIAMPHORA

Heliamphora nutans, H. neblinae, H. ionasi, H. tatei, H. minor, and H. heterodoxa are the 6 recognized species. Heliamphora minor is the most diminutive of the genus [2-3 in. (5-8 cm)] while H. tatei var. tatei is the largest, with a dendroid growth habit reaching 3-5 ft. (0.9-1.5 m), and in sparsely populated areas climbs to heights of 13 ft. (4 m).

DESCRIPTION OF THE SPECIES

H. heterodoxa Steyermark. Pitchers up to 12 in. (30 cm) long on stems with a pronounced constriction just above the center.

var. exappendiculata has a vestigial hood and pink flowers.

var. glabra has no pubescence on the upper internal surface of the pitcher and has white flowers.

var. heterodoxa is pubescent on the upper internal surface of the pitcher. Flowers white to pink, pitchers with some red coloration.

H. ionasi Maguire. Pitchers up to 20 in. (51 cm) long, reddish in color and forming rosettes. They have a definite constriction near the top. Flowers first white then turning red.

H. minor Gleason. Pitchers 2-3 in. (5-8 cm) tall with a constriction near the top and a small apical cap or hood whose inner surface is red.

H. neblinae Maguire.

var. neblinae Pitchers usually exceeding 10 in. (25 cm) in length. Leaves pubescent with short hairs and having a prominent pore and weakly developed hood. Perianth frequently 5-6 parts, white turning pink.

var. viridis Same as var. neblinae except perianth is greenish and has 4 segments.

var. parva Pitchers usually less than 8 in. (20 cm) long, externally glabrous with an inconspicuous pore. Plants usually have a red-tinge. Perianth white with some pink later turning maroon.

TEPAL

TEPAL

Flower Long Section
Fig. 3-26 Longitudinal-section of Heliamphora flower. The pubescent ovary is surrounded by 10 stamens.

Fig. 3-27 Longitudinal-section of Heliamphora pitcher. The lowermost region has sharp downward pointing hairs. The middle region is smooth, offering no foothold to an insect. The uppermost region has long flexible hairs intermingled with nectar glands. The lid contains numerous necta secreting glands.

Ala Heliamphora

HOOD WITH NECTAR GLANDS

DOWNWARD POINTING HAIR AND NECTAR GLANDS

Fig. 3-27 Longitudinal-section of Heliamphora pitcher. The lowermost region has sharp downward pointing hairs. The middle region is smooth, offering no foothold to an insect. The uppermost region has long flexible hairs intermingled with nectar glands. The lid contains numerous necta secreting glands.

SMOOTH WALLS DOWNWARD POINTING HAIRS

HOOD WITH NECTAR GLANDS

SMOOTH WALLS DOWNWARD POINTING HAIRS

DOWNWARD POINTING HAIR AND NECTAR GLANDS

H. nutans Bentham. Pitchers 4-6 in. (10-15 cm) long with a constriction near the top. Internal surface of hood is red. Flower white turning red. H. tatei Gleason.

var. tatei Dendroid growth reaching heights of 3-5 ft. (0.9-1.5 m) in dense populations, growing to 13 ft. (4 m) in open areas. Pitchers reach 14 in. (36 cm) in length growing from shrubby stems. Pitchers internally pubescent, perianth 4 parted, white turning red. var. macdonaldae Same as var. tatei except pitchers are internally glabrous save at the mid-zone.

CULTURAL INFORMATION

Planting Media

Living or non-living sphagnum moss, a mixture of sphagnum peat moss and sphagnum moss, or a mixture of sphagnum moss and perlite. Yearly repotting is recommended.

Temperatures

The range in their native habitat is 38-78°F (3-26°C). Temperatures in cultivation should not be allowed to go above 78°F (26°C) for any length of time. Recommended: summer 55-75°F (13-24°C), winter 40-60°F (4-16°C).

Dormancy

There is no true dormancy period, but in cultivation the rate of growth is considerably reduced and few are leaves produced during the winter.

Water & Humidity

Heliamphora plants require high humidity and daily watering during the summer. During periods of high temperatures, the plants may need watering several times a day to prevent temperatures from reaching the upper limit. Keep the soil drier during the winter season.

Light

Heliamphora require strong light for maximum growth and will tolerate full sunlight, producing vigorous healthy plants. In their native habitat, the soil and air remains relatively cool under full sunlight because of the high elevation, whereas in a greenhouse, exposed to full sunlight, soil and air temperatures rise considerably above the level to which the plants are adapted. Make provisions for maximum light with soil and air temperatures not exceeding 78°F (26°C). Under artificial light provide an intensity of at least 1500 foot candles with a summer photoperiod of 13-14 hours and a winter photoperiod of 12-13 hours.

Pests

Known pests are aphids and Botrytis. See Chapter 8 for control. Feeding

Many growers have indicated that fertilizing Heliamphora often results in death of the plant.

Miscellaneous

The easier species of Heliamphora to grow are H. heterodoxa, H. nutans, and H. minor.

PROPAGATION

Sexual Reproduction

The stigma is receptive to pollen for a few days immediately following the opening of the flower, while the anthers produce mature pollen about one week after the stigma has ceased to be receptive. Because of the timing of pollen maturation and stigma receptivity, the pollen from one flower cannot pollinate a pistil in the same flower. Therefore, two or more flowers must be mature at about the same time or the pollen from one flower must be stored for a few days until a stigma in another flower is receptive. There are no reports of anyone trying to store Heliamphora pollen for later use. It may well be that this pollen can be stored under refrigeration as can that of Sarracenia.

When the anthers are mature they will swell and split to release their pollen. Sometimes the anthers will swell and become yellowish green, indicating that pollen has formed but will not release the pollen. In this situation, try teasing the anthers with a pair of forceps or with a pin-point to open the cavity and release the pollen. If this fails, pull the anther apart to free the pollen. An alternative is to remove the anthers and allow them to dry for a day or two and then gently take them apart if drying does not induce dehiscence.

The oval-shaped seed, is sown on the medium surface and maintained in a humid environment out of direct sunlight and within a temperature range of 68-72°F (20-22°C). Germination will usually occur within three months. Growth of plants from seed is a slow process which may indicate that there are some special growing requirements that have not yet been ascertained.

Asexual Reproduction

Crown or rhizome division:

Heliamphora plants develop growing points on the rhizome or stem that will produce new plants. The new plants can be separated by cutting them apart from the mother plant. This is most successfully done during the spring or early summer. It is particularly important with this genus to avoid damaging the roots when making the separation of crowns and transplanting them. Plant the crown divisions in the medium and maintain a high humidity under strong light within a temperature range of 55-75°F (13-24°C).

2-1. Dionaea muscipula plants. Red coloration of traps indicates good lighting conditions in most cases.

2-2. Dionaea muscipula leaf. Trigger hairs are arranged in a triangular pattern on the inner lobes of the trap. The margins of the trap are studded with bristles.

2-3. Dionaea muscipula leaf with captured insect. During the narrowing phase of capture, the lobes can become so tightly pressed together that the outline of the captured prey is visible.

2-4. Dionaea muscipula leaf section with plantlets. Leaf cuttings placed on damp medium, kept in bright light and in moist environmental conditions, produce buds that develop into plantlets.

2-4. Dionaea muscipula leaf section with plantlets. Leaf cuttings placed on damp medium, kept in bright light and in moist environmental conditions, produce buds that develop into plantlets.

Dionaea Muscipula Bear Trap
3-1. Sarracenia oreophila growing in natural habitat in southeastern United States.

3-2. Sarracenia leucophylla leaf. Showing coloration of the leaf, fenestrations and secretion of nectar.

3-3. Sarracenia minor leaf. Fenestrations, translucent area lacking pigment, allow light to pass through. Insects on the rim of the pitcher, looking up, mistake the fenestrations for openings, fly into them, and drop to the bottom of the pitcher.

3-5. Sarracenia psittacina plants with flowers. Petals are maroon with cream apices.

3-5. Sarracenia psittacina plants with flowers. Petals are maroon with cream apices.

3-4. Flower of Sarracenia purpurea ssp. purpurea f. heterophylla. This form of S. purpurea lacks the usual maroon-red coloration in the vegetative parts and in the flower.

3-7. In nature, the pitchers, filled with rainwater and enzymes, await prey. Nepenthes ampullaria. (Photo by Bill Hanna)

3-6. Staminate flowers of Nepenthes. The flowers lack petals, have four sepals and golden colored anthers. The sequence of flower opening is from the bottom of the inflorescence toward the top.

3-9. Nepenthes gracilis lower pitcher. (Photo by Bill Hanna)

3-8. Nepenthes ampullaria pitcher. The small ellipsoidal trap has a deep red collar and a small reflexed lid.

3-10. Darlingtonia californica plant. Pitchers twist so that the opening, from which hangs a fang-like appendage, faces outward from the center of the plant. The translucent areas are fenestrations.

3-9. Nepenthes gracilis lower pitcher. (Photo by Bill Hanna)

3-11. The jug-shaped pitchers of Cephalotus form a ring around the rosette of foliage leaves. The openings of the pitchers are oriented outward from the center of the plant.

3-10. Darlingtonia californica plant. Pitchers twist so that the opening, from which hangs a fang-like appendage, faces outward from the center of the plant. The translucent areas are fenestrations.

3-13. Cephalotus seeds are borne individually within pubescent fruits that emerge from the flower.

4-2. Drosera paleacea plant with flowers. The plant produces layers of new leaves on top of the older ones.

4-1. Pygmy Drosera with flat, discshaped gemmae in the center of the plant.

4-3. Drosera pulchella plant with flowers. The leaf blades are circular.

4-1. Pygmy Drosera with flat, discshaped gemmae in the center of the plant.

4-3. Drosera pulchella plant with flowers. The leaf blades are circular.

Drosera Paleacea Ssp Paleacea

4-2. Drosera paleacea plant with flowers. The plant produces layers of new leaves on top of the older ones.

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4-6. Drosera gigantea tuber. Scales are visible on the tuber. New growth is emerging from the center.

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4-12. Drosera capensis leaves are erect with a linear leaf blade.

Linear Leaf Apex

4-11. Drosera binata var. multifield leaf blade with many divisions.

4-13. Drosera adelae plants.

4-11. Drosera binata var. multifield leaf blade with many divisions.

4-13. Drosera adelae plants.

4-12. Drosera capensis leaves are erect with a linear leaf blade.

4-14. Drosera petiolaris plants. Leaf color is pale due to heavily pubescent petioles.

4-14. Drosera petiolaris plants. Leaf color is pale due to heavily pubescent petioles.

4-19. Byblis gigantea plant with flower.

5-1. The corolla of Pinguicula flowers narrows to form a pointed spur. The palate is the pubescent structure on the lower lip of the corolla. Pinguicula vulgaris.

4-20. Byblis liniflora flower has 5 petals, 5 sepals and 5 stamens.

4-19. Byblis gigantea plant with flower.

4-20. Byblis liniflora flower has 5 petals, 5 sepals and 5 stamens.

5-1. The corolla of Pinguicula flowers narrows to form a pointed spur. The palate is the pubescent structure on the lower lip of the corolla. Pinguicula vulgaris.

5-3. Pinguicula caerulea plant growing in natural habitat.

Pinguicula Caerulea

5-3. Pinguicula caerulea plant growing in natural habitat.

5-4. Pinguicula longifolia flower.

5-2. Pinguicula longifolia plant. Leaves tend to curl up during and after prey capture to form a shallow bowl which contains the digestive fluids and prevents loss of prey.

5-4. Pinguicula longifolia flower.

5-5. Pinguicula moranensis plant with flower.

5-5. Pinguicula moranensis plant with flower.

5-6. Winter bud of Pinguicula longifolia with smaller brood bodies in foreground.
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5-7. Leaf of Pinguicula with small plantlets.

6-1. Terrestrial Utricularia plants. The surface leaves are photosynthetic . Rhizoids which bear bladders anchor the plant in the growing medium. Sometimes grow out of the growing medium.

5-7. Leaf of Pinguicula with small plantlets.

6-1. Terrestrial Utricularia plants. The surface leaves are photosynthetic . Rhizoids which bear bladders anchor the plant in the growing medium. Sometimes grow out of the growing medium.

6-4. Reproductive structures of Utricularia longifolia. The two curved stamens are below the stigma.

6-5. Utricularia inflata, an aquatic bladderwort. (Photo by O.H. Weiss)

6-6. Utricularia menzeisii plants form dormant structures during the dry season. Many white rice-like structures are enmeshed within a fibrous network.

6-7. Polypompholyx multifida plants in natural habitat.

6-8. Aldrovanda plant.

6-6. Utricularia menzeisii plants form dormant structures during the dry season. Many white rice-like structures are enmeshed within a fibrous network.

6-8. Aldrovanda plant.

Aldrovanda

9-1. Rhizome proliferation is encouraged by removing leaves from rhizome and cutting off growing tip. The remaining portion of the rhizome is planted halfway into the growing medium. Buds will develop into plants that can later be separated from each other.

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