Heliamphora
Content
Description
Phyllodes present, often conspicuous; pitchers ventricose or essentially tubular, up to 50 cm long, outside with scattered bifid hairs and small glands, base attenuate, ventral wings paired, apical leaflet small (absent in H. macdonaldae Gleason), cup-shaped with narrow base, not covering the pitcher mouth, inside producing nectar. Inflorescences racemes; peduncle exceeding leaves; bracts foliaceous; bracteoles absent; pedicels slender and drooping or stout and erect, glabrous to densely pubescent. Flowers nodding; sepals 4(-6), petaloid, white to red, glabrous; petals absent; stamens 10-numerous, 1-cyclic, filaments stout, thick at base, anthers basifixed, sagittate, during anthesis reflexing from introrse to extrorse, dehiscing through upwardly directed, caudal appendages; pollen subglobose, ca. 30-35 x 20-25 μm, (3-)4-5-colporate, exine verruculate; ovary, 3(-4)-locular, densely covered with bifid hairs, style slender, cylindrical, glabrous, stigma shallowly truncately 3(-4)-lobed. Capsules splitting downwards in three parts, held together by the style; seeds ovoid, glabrous, irregularly scario-fimbriately winged, embryo small, embedded in copious endosperm. Chromosome number 2n = 42 (Maguire, 1978).
Distribution
Guayana Highlands present, Guyana present present, Mt. Roraima present, Southern America: Brazil North (Roraima present); Venezuela (Venezuela present)
Species 6, in the Guayana Highlands (Roraima Formation of southern Venezuela, contiguous Guyana and Brazil); in Guyana only one species from Mt. Roraima.
Notes
The number of species is not certain. Maguire (1978) stated that "several populations of possible narrow genetic differences are held intact because of geographic isolation". Further research is needed to answer the questions about the number of species and their limits.
The indument on the inner side of the pitcher is highly specialised. The upper part of the pitcher is covered with many strong, long, downwardly directed, non-secreting hairs (H. macdonaldae Gleason glabrous), the middle part is glabrous and the lower part covered with scattered, smaller, rougher, reflexed hairs. The hairs from the lowest part have the appearance of secreting hairs.
Many authors have already mentioned the carnivorous function of the pitchers.
Living creatures have been found inside the pitchers, such as bacteria, amoebae and insects. Most of the data are fromSarracenia species, hardly anything is known from Heliamphora species. Only Uphof (1936) mentioned flies and butterflies in H. tyleri Gleason .
Parasitic fungi were found onSarracenia species (Tracey & Earle, 1896; Uphof, 1936), but no data are yet known from Heliamphora species.
Halfway the pitcher, just above the basal part, a small pore in the seam is present. Through this pore the plant can get rid of the water surplus from heavy rainfall. Downward directed hairs as present at the inside of the pitcher prevent insects from escaping the pitcher through the pore. The pore is difficult to see, because it is situated between the lateral wings. As a result of the pressing of the plant, this pore is usually not visible in herbarium specimens.
The indument on the inner side of the pitcher is highly specialised. The upper part of the pitcher is covered with many strong, long, downwardly directed, non-secreting hairs (
Many authors have already mentioned the carnivorous function of the pitchers.
Living creatures have been found inside the pitchers, such as bacteria, amoebae and insects. Most of the data are from
Parasitic fungi were found on
Halfway the pitcher, just above the basal part, a small pore in the seam is present. Through this pore the plant can get rid of the water surplus from heavy rainfall. Downward directed hairs as present at the inside of the pitcher prevent insects from escaping the pitcher through the pore. The pore is difficult to see, because it is situated between the lateral wings. As a result of the pressing of the plant, this pore is usually not visible in herbarium specimens.