Pollination Ecology of Pedicularis megalantha D. Don (Scrophulariaceae) in the Himachal Himalaya

Abstract

In the summer of 1990, the pollination ecology of Pedicularis megalantha was studied in the montane‐subalpine spruce‐fir forest zone (2750‐3050 m) on the north slope of Mt. Huttoo at Narkanda, Himachal Pradesh, in the Indian Himalaya. Its yellow, long‐tubed, nectarless flower with a curled rostrum overarched by a broad, inverted lower corolla lip was pollinated exclusively by Bombus albopleuralis and B. tunicatus workers hanging inverted from the corolla and vibrating pollen from introrse anthers concealed within the galea and releasing pollen through a small ventral opening in the galea base. The stigma, protruding from the tip of the rostrum, contacted pollen deposited on the ventral side of the insect's thorax. Corbicular pollen loads from P. megalantha pollinators indicated equal numbers of monolectic and oligolectic foragers. P. megalantha appeared to suffer from competition for pollinators by Cynoglossum wallichii at one site but to be favored in a mixed plant community with nectariferous species offering a forage resource complementary to Pedicularis pollen. As in P. punctata, the long, nectarless corolla tube of P. megalantha appears to function in extending the rostrate vibration pollination mechanism beyond the plant's foliage, which would interfere with its function. It is not an adaptation for nectar‐foraging lepidopteran pollinators. P. megalantha was also found to be a root hemiparasite.

The pollination ecology of Pedicularis rex subsp. lipkyana and P. rex subsp. rex (Orobanchaceae) from Sichuan, southwestern China

“…It is one of the plant genera that have attracted extensive pollination studies. So far these studies have shown the only effective pollinators to be bumblebees (Sprague, 1962;Macior 1968aMacior , b, 1969Macior , 1970Macior , 1973Macior , 1975Macior , 1977Macior , 1978Macior , 1982Macior , 1983Macior , 1986aMacior -c, 1988Macior , 1990Macior , 1993Macior , 1995aMacior , b, 1996KoemanKwak, 1973KoemanKwak, , 1977KoemanKwak, , 1979Williams and Batzlli, 1982;Aluri and Robart, 1991;Eriksen et al, 1993;Macior and Sood, 1991;Philipp et al, 1996;Macior and Tang, 1997;Wang, 1998;Wang andLi, 1998, 2005;Macior et al, 2001;Tang and Xie, 2006). This does not support speculations that pollinators of Pedicularis species would be as diverse as the floral morphology implies or that species with extremely elongated corolla tubes might require specific pollinators of lepidoptera or other insects with very long proboscides (Pennell, 1948;Li, 1948Li, , 1951.…”

Revision of the Limits of Pedicularis Series Megalanthae (Prain) Bonati (Orobanchaceae)

“…Prain (1890) mentioned that forms from the NW Himalaya differed in their wholly goldenyellow corollas but these were included by Pennell (1943) in his concept of Pedicularis hoffmeisteri. Macior & Sood (1991) regarded Pedicularis hoffmeisteri and P. megalantha sensu stricto as colour morphs but their view is not accepted here because of the other correlated character differences. These include filament indumentum (both pairs of filaments villous in Pedicularis hoffmeisteri, only the anterior pair hairy in P. megalantha), and smaller anthers compared with P. megalantha.…”

“…These four taxa, incidentally, all deserve separate species rank. Pedicularis hoffmeisteri has previously been sunk into P. megalantha, either as a variety (Sealy, 1939) or as a synonym (including, importantly, in the pollination paper by Macior & Sood, 1991; others taking this view have been . However, it differs from true Pedicularis megalantha in several correlated characters.…”

“…The two species are also disjunct, Pedicularis hoffmeisteri occurring in Himachal Pradesh and western Nepal, while P. megalantha is restricted to C and E Nepal, Sikkim, southernmost Tibet (Xizang: Chumbi) and Bhutan. The species with yellow corollas from the Himachal Himalaya whose pollination biology was studied by Macior & Sood (1991) was actually Pedicularis hoffmeisteri, not P. megalantha as stated by the paper's authors. Pedicularis hoffmeisteri and P. megalantha have also been regarded as distinct species by Aswal & Mehrotra (1994) and most recently by Garg (2009).…”

“…(now regarded as the species P. pauciflora; see above). Limpricht regarded Pedicularis hoffmeisteri as a mere synonym of P. megalantha and some authors (notably Macior & Sood, 1991) have followed that view while others (e.g. Pennell, 1943;Yamazaki, 1982Yamazaki, , 1988 have retained the two as separate species.…”