Nestled at the base of the conifer collection and straddling the banks of Bussey Brook stands one of the most picturesque plantings in the Arboretum: a grove of mature golden larches, Pseudolarix amabilis. In the winter, one marvels at their stately, flat-topped form; girthy branches defying gravity. Each spring, from small branch spurs, new leaves flush greenish-yellow before turning dark green by mid-summer. But, it is in autumn that the species takes on its true majesty, when the leaves seem to be on fire, becoming the intense golden-yellow that gives the species its common name.
Pseudolarix is a monotypic genus (i.e., it has but one species), and is a moderately rare tree of east-central China. It resembles the true larches (Larix) by having both long- and short-shoots (spurs) and deciduous leaves, however the male cones are borne in clusters at the ends of the short shoots as are the solitary female cones, which resemble miniature artichokes before disintegrating as they release their seeds.
Robert Fortune, the famous Scottish plant explorer responsible for innumerable horticultural introductions from Asia, first collected seeds of Pseudolarix in modern-day Zhejiang Province, China, in the autumn of 1853. Some of the massive trees he found in the wild reached impressive sizes, oftentimes exceeding 35 meters (115 feet) in height. Although he collected seeds, germination was very poor and most of the plants first in cultivation in the west were seedlings brought back in the infamous Wardian cases.
By the 1870s, cultivated European trees began producing seeds, and many nurseries in the UK were offering young plants for sale. However, it was not until May of 1891 that the Arboretum received its first plants from the English firm of Veitch and Sons. These two individuals, accessions 3656-A and 3565-B, were planted on opposite banks of Bussey Brook. They continue to thrive, and 3656-B stands tallest in the collection, with a height of 24.5 meters (80 feet) and a DBH of 80 centimeters (2.5 feet). In 1896, the Arboretum received seed from the Hunnewell Pinetum in Wellesley, Massachusetts, which was collected from a mature tree Horatio Hollis Hunnewell had purchased from Veitch back in 1866. Two plants of this 1896 seedlot, accessions 16779-A (see facing page) and 16779-B, also grow on the banks of Bussey Brook; 16779-B has the stoutest stem of any in the collection, with an impressive diameter at breast height of 91.4 centimeters (3 feet). A bit higher up on the slope stands accession 10764- A, another plant received from the Hunnewell’s on April 22, 1921 with the moniker Pseudolarix amabilis nana. However, this tree did not live up to its dwarf name, for by 1946 it was at least 9 meters (30 feet) tall, prompting Heman Howard to note in the records: “nothing ‘nana’ about this plant.” By coincidence, the Arboretum’s archives contain a photograph taken by Alfred Rehder on June 21, 1921 of a ‘dwarf’ Pseudolarix growing in a container; most likely the same individual. Despite being 30 years younger than the two oldest specimens, this tree is nearly as tall, with a height of 21.1 meters (70 feet). The only wild-collected golden larches in the Arboretum came from Tian Mu Shan, Zhejiang Province, and are represented by 5 plants in accession 187-94. Plant A of this accession was planted in the Bussey Brook grove in 2000 and has grown very well, already reaching 8.2 meters (27 feet) in height.
The next time you come to the Arboretum, be sure to visit the grove of golden larches—each season reveals a bit of its personality. As you stroll Conifer Path and cross the bridge over Bussey Brook, you can admire their majesty and reflect upon their history.
Michael Dosmann is Curator of Living Collections at the Arnold Arboretum.