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)
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, 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.
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)
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.
Was this article helpful?