Rosa macrophylla

Family / Families: Rosaceae
Scientific Name(s): Rosa macrophylla Lindl.
Institution(s): David C. Lam Asian Garden, University of British Columbia Botanical Garden
Accession Number(s): 1986-0524
Location(s): Vancouver, British Columbia, Canada
Entry Author(s): Dominic Janus
Copyright Holder(s): Dominic Janus
Image License: Creative Commons License
Tags: Photo by Dominic, Rosaceae, Rosales, UBC Botanical Garden

The vegetative stem and prickles of Rosa macrophylla

This recently identified rose species in UBC Botanical Garden was received from plant explorer Keith Rushforth. Originally received as Rosa sp. (with an affinity [similarity] to Rosa macrophylla), the writing of this entry prompted an examination of the plant (now that it’s mature) to confirm its identity. Seed collected by plant explorers typically occurs when plants are senescing, so traditional identifying characters are often unavailable (e.g., flower size, stamen length, or presence of glands on new growth); identification may have to wait for several years, assuming the seeds germinate.

This plant somewhat merges characteristics from two plants I wrote about during my time as a BPotD Work-Learn student: the well-known Rosa canina (dog rose) and Bistorta affinis (Himalayan bistort). Rosa macrophylla is an alpine shrub. Although it is similar in appearance to dog rose, it can be found in the same plant communities as Himalayan bistort. Rosa macrophylla grows at high elevations from 2400-3700m (7900-12150 ft.) in many alpine habitats from Afghanistan to China.

The specific epithet, macrophylla, means to have large leaves. Seemingly lacking an English common name, I’d say “large-leaved rose” would be appropriate. The leaves are known to be variable in shape and size, but range from 7-15cm (and sometimes 25cm!) in length (3-6[10] inches). As with most species of Rosa, the vitamin C-rich fruits (hips) are edible. However, care is required when ingesting–small hairs on the seeds of the fruit can cause irritation.

This shrub has many densely-arranged stems, each heavily armed with these robust prickles that caught my attention. It gives it quite the impenetrable look! Much to the credit of a Disanthus cercidifolius in the background, I was able to get arguably the most colourful backdrop possible (this photograph was taken in autumn). The prickles are originally green on young stems, but turn almost white as the stem ages and turns chestnut brown–a wonderful contrast.

As a side note, here is the difference between prickles, thorns, and spines. Thorns are modified stems, while spines are often modified leaves or stipules. Both of these tend to be quite long and sharp. Prickles however, are outgrowths from the epidermis of the stem tissue; all roses have prickles. I’ve definitely been guilty many times of making the incorrect distinction, especially confusing rose prickles with thorns.

Rosa macrophylla appears in a study that discusses the potential value of non-timber forest products in improving both biodiversity conservation and the standard of living in central Himalayan communities. It is noted that the flowers of Rosa macrophylla could be (are) used in beverages (juices) while the fruits could be (are) harvested for food or medicine. Conservation of biodiversity linked to socio-economic development in smaller communities is a positive trend. From a faunal biodiversity perspective, wildlife conservancies are successful examples. However, if you’re unaware of the ironic role of hunting as a key dynamic surrounding large mammal conservation in Africa, read this article.