When is a pine not a pine, or an oak not an oak? These seemingly simple questions could involve a lifetime of study for the plant systematist. The concepts of genus and species have been with us for more than two centuries, and even today, scientists wrestle with whether they are valid. The boundaries that separate one species from another can be unclear, and it is often the plants at the edges of a definition-whether a genus or a species-that present the greatest challenges to the taxonomist. Does an aberrant or highly distinct population of plants warrant a new species designation? Is it so unusual that it represents a new genus, or even a new family?
The group of gymnosperms we know by the common name of pine belongs to the genus Pinus, which includes over 100 accepted and described species. Occurring primarily in the Northern Hemisphere, the genus has one of the widest natural distributions of any group of trees on the planet. Pines can be found growing from 70 degrees north latitude in Siberia to below the equator on Sumatra. Pinus rigida is bathed by ocean spray on the coast of New England, while pines in Mexico and the Himalayas grow 10,000 feet above sea level. Experts on the genus Pinus put all pines into one of two subgenera. Strobus (Haploxylon) contains the soft or white pines, while Pinus (Diploxylon) are the hard pines. In 1966, Critchfield and Little proposed a third subgenus, Ducampopinus, containing only the species Pinus krempfii.
A tall pine native to the tropical forests of Vietnam, Pinus krempfii is probably the most poorly known and least understood in terms of its taxonomic placement. It is a highly unusual pine, as its leaves are broad and flattened rather than being needlelike. In its native forests, where it can only be found with some difficulty, it grows to a colossal height, towering over the surrounding flora. Described in 1921 by French botanist Henri Lecomte and named for the discoverer M. Krempf, it has never been widely collected, and as far as I could determine, no specimens are in cultivation outside of Vietnam. Recent taxonomic research suggests that the species is closely related to the bristlecone and pinyon pines, but there is still a lack of consensus about this rarity. It was decided that collecting live material for genetic analysis would give researchers the DNA needed to solve this puzzle.
In the autumn of 1998 I teamed with Dr. Shu-Miaw Chaw of the Academy of Sciences in Taipei, Taiwan, to collect rare conifers of Taiwan and Vietnam. We wished to bring into cultivation many rare and endangered species for future research purposes, and Dr. Chaw was to collect DNA samples of conifers for her work on the evolution and phylogeny of gymnosperms. Our research team was to have an extraordinarily successful trip, and the Lyman Conservatory now houses such rarities as Amentotaxus formosana, Cephalotaxus wilsoniana, Cephalotaxus mannii, Calocedrus macrolepis, Taxus wallichiana, Keteleeria evelyniana, Podocarpus neriifolius, and the only known plants of Pinus krempfii in North America.
We began our journey with a visit to Dr. Le Thi Xuan, the head of the Biotechnology Institute, whom we knew from prior collecting trips. She had been instrumental in linking us to Dr. Tran Ngoc Ninh, a capable field botanist who accompanied us on our expedition. As we were leaving, she pulled us aside and said, "Be careful in the Dalat Forest, it is full of danger."
"What kind of danger," I replied, "two-legged or four-legged?"
"Danger of every kind," was her parting comment.
After two flights we landed at Dalat airport, then drove upward into the hills. On the town's outskirts lay the Biological Institute, located in a former Catholic monastery. It was built by Catholic monks in 1950 but lost to the Communist takeover in 1954. Despite the apparent low budget, the institute has a tissue culture |
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Pinus krempfii, from Buchholz, J. T.,
"A flat-leaved pine from Annam, Indo-China," 1951, in American Journal of Botany 38: 245-252
lab and is involved in conserving the many endemic plant and animal species of the region. In the small nursery outside grew a number of conifer species we had sought, including Taxus wallichiana, Dacrydium elatum, Fokienia hodginsii, and Podocarpus neriifolius.
The former Director of the Arnold Arboretum, Dr. Peter Ashton, had been to Dalat and related to me that a specimen of the rare Pinus krempfii grew in a park at the outskirts of town. We first checked the Valle d'Amour Park with no success. But at Cong Ty Park we found a Keteleeria evelyniana in cone and then 50 feet away the prize, a specimen of Krempf's pine. It looked like a broad-leaved Podocarpus from only 10 feet away, but on close examination it held its new "candles" like a pine and did indeed smell like a pine when crushed. We happily collected needles and herbarium specimens.
A hard rain threatened our scheduled departure, but the dawn broke clear as we began to pack our war-vintage Russian jeep. We piled in, and as we drove out of town, armies of schoolchildren trudged down the road toward the morning's classes. Nine kilometers out from the institute we halted beside a roadside grove of Keteleeria evelyniana. Belonging to the pine family, keteleerias grow well in our southern states but are poorly known horticulturally and taxonomically. We continued on the muddy red-orange road, passing a small reservoir and hydroelectric plant and crossing a very suspect bridge into an unpopulated and relatively undisturbed geography. Shouldering our packs, we marched out, over the crest of a small hill. Rising above a primeval evergreen forest was the pine we had come so far to see
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