10 New Plant Species Described by the Missouri Botanical Garden in 2020

Each year, the Missouri Botanical Garden’s Science and Conservation staff discover and name about 200 plant species new to science. That’s roughly 10 percent of all plant species discovered by scientists worldwide annually.

Discovery is the first crucial step in plant conservation. Until a species is described, we cannot think about conservation status or ensure its survival. Once described, species need to be organized into classification systems. These classifications provide meaningful ways to talk about plants and plant diversity and are a basic need for other types of plant science.

Even with many changes due to the pandemic, the Garden’s Science and Conservation team has been able to forge ahead with these efforts, identifying new species from herbarium specimens collected years ago and earlier field studies.

We’re still counting the number of new species discovered by the Garden this year, but here are a few highlights.

Diospyros hongwae

In Madagascar, precious woods, in particular ebony and rosewood, are threatened by deforestation and illegal harvesting for export. The Garden is working to save these species, starting with taxonomic studies as an essential first step. In 2020, Garden botanists George Schatz and Pete Lowry described 10 new species of ebony from Madagascar, which belong to the genus Diospyros. This is the latest advance in their study, which will nearly triple the number of recorded species, from about 85 when they began their work a decade ago to 250 species that they now recognize. All but three of those species occur nowhere else in the world.  

Among the ebonies described in 2020 is Diospyros hongwae, an endangered species named in honor of Cynthia Hong-Wa, a Malagasy student who completed her Masters and Ph.D. studies at the Garden and UMSL. It is known from only two dry forest sites in northwestern Madagascar. Diospyros is the source of rich, black ebony wood, a valuable and highly prized hardwood obtained from species occurring in many tropical areas.

Drosera arachnoides

Spider-like in both its appearance and appetite, Drosera arachnoides is a newly described species found only in Madagascar. Also known as the spider sundew, this carnivorous plant uses its sticky leaves to capture and devour insects. Garden ethnobotanist Nivo Rakotoarivelo first noticed the plant in 2010 while doing fieldwork in Vohibe Forest, a protected site managed by the Garden’s William L. Brown Center. Nearly a decade later, Rakotoarivelo and other Garden researchers returned to the site to learn more about the spider sundew’s surrounding habitat, take pictures, and gather herbarium specimens to support its description as a new species.

Fewer than 1,000 individuals of Drosera arachnoides have so far been found in the wild. And while the site in Vohibe Forest is in a protected area, there is a risk human interference or natural events could quickly and dramatically reduce that population.

Planetangis

A favorite of many, the orchid family, Orchidaceae, is one of the largest and most charismatic plant families with at least 28,500 species worldwide. But much is still unknown about its evolutionary background. In the past two decades, more efforts have been made to better understand that history and to produce a more natural classification of the family.  As part of these efforts, in 2020 Garden Researcher and orchid expert Tariq Stevart, along with colleagues described a new genus of orchid, Planetangis, which had previously been artificially group with other species that shared the same overall floral morphology but had different evolutionary stories.

Planetangis grows as an epiphyte on large tree branches in lowland evergreen and semi-deciduous rainforest in an area stretching from Liberia in West Africa to Gabon in Central Africa. As with many orchids, it was collected without flowers and brought back to a shade house until it flowered, so Garden orchid expert Tariq Stevart could identify it as new to science.  

Heliophila goldblattii 

Garden Resarcher Ihsan Al-Shehbaz has spent 53 years studying the mustard family, so he’s more than familiar with the more than 4,000 species in the family. In 2020, he discovered 10 new species of the South African genus Heliophila. The genus exhibits the most diversity of habit in the entire family, as it includes two species of trees, a species of vine, several shrubs, and perennial and annual herbs, some of which barely exceed two inches in height. It includes at least 105 species, all of which are native to South Africa. While part of the mustard family, no member of this genus is consumed by people, but due to their appealing looks, several species are grown as ornamental plants. 

Heliophila goldblattii, a delicate annual herb only 4-12 inches tall with small purple flowers, was named in honor of Dr. Peter Goldblatt, curator emeritus of the Missouri Botanical Garden, who was among the first to collect this novelty over forty years ago. Peter Goldblatt was a world expert on the iris family.

Homalium phillipsonii 

This shrub, which can sometimes grow to a tree 15 meters tall, has attractive cylindrical racemes of white flowers. It is native to southwestern Madagascar, a dry part of the country with a harsh environment. It is provisionally assessed as “vulnerable,” hence of moderate concern of extinction. It’s found in a limited number of places and some of the historical populations are now probably extinct. This was described by Garden Researcher Wendy Applequist and colleague Anna C. Wassel, who reviewed the genus and recognized ten species within that species complex, all of which have much more narrow distributions, and six of which are threatened or endangered.  The species is named for Garden Curator Pete Phillipson. Phillipson collected the specimen that would be identified as Homalium phillipsonii, in 1989 in the Zombitsy forest. Zombitsy and the nearly Vohibasia forest are isolated forest patches that were known to contain numerous locally endemic species, but the area was subject to extensive forest clearance for shifting agriculture. Phillipson could see smoke rising from the fires burning in the forest. Recently ,Zombitsy was designated a protected area and measures are being taken to protect the forest and to develop alternative sustainable livelihoods for the people of the region.

Polystichum asiae-minoris

Added to the list this year is Polystichum asiae-minoris which grows on limestone bedrock, in humid and shady conditions. Associate Curator Libing Zhang identified this as new from a specimen from Turkey, which is located at the intersection of three biodiversity hotspots, the Mediterranean, Caucasian, and Irano-Anatolian, making it home to remarkable levels of plant diversity. P. asiae-minoris, however, is enigmatic in having no biogeographic connections to those three areas. Scientists wonder if its relatives are found in East Asia, the Antillean islands, or the Americas, and how and when its ancestor arrived in Turkey. They will conduct molecular phylogenetic analysis to learn more about its origin. 

Entosthodon elimbatus

This moss grows on soil in rock fissures at an elevation of 3,590 meters in southwestern China. A colleague sent this specimen to Garden Researcher Si He, an expert in Chinese mosses, who identified new characteristics not previously found in the genus. Entosthodon elimbatus is from a sub-alpine area in Yunnan, China and appears to be rare.

Blephilia woffordii

Not all new species are found in faraway, tropical countries. Garden researcher Aaron Floden found this odd-looking wood mint in Middle Tennessee. It has upright stems and glossy, nearly hairless leaves, unlike the other two species known from the state. It has been found to grow in four locations, all along the steep bluffs of a 6-mile stretch of the Caney Fork River. It will soon receive protected status in Tennessee. Back home in St. Louis, Floden has the species in cultivation and found it is easy to grow from seed.

Faramea stoneana

Photo courtesy of Digital Flora of La Selva. Photo by Reinaldo Aguilar.

Often, describing a new species is a process years in the making. Garden Research Charlotte Taylor, for instance, had been studying the flowers, fruits and other characteristics of a certain plant from specimens collected by various researchers over a 40-year period. In 2020, she finally had enough material to officially describe Faramea stoneana, a small forest tree found from Central America through western South America. The bright white flowers are easy to spot in the dark forest understory, and the fruits are small bluish black “cherries” that are dispersed by birds. No one knows much about the biology of this species yet, even though it is common at the well-studied La Selva Biological Station in Costa Rica. This field station is run by the Organization for Tropical Studies (OTS) for teaching and research, and has two-thirds as many plant species as all of Missouri in just about 6 square miles. OTS was led and extensively developed for several decades by Dr. Don Stone, and the name of this elegant species honors him.

Sciodaphyllum zarucchi

Nearly all members of the ivy and ginseng family, Araliaceae, are tropical trees and shrubs, a group that Garden botanist Pete Lowry has studied throughout the world over the last four decades. In 2016, he began focusing on the genus Sciodaphyllum in the northern Andes of South America, where more than 100 species have been described and at least as many more remain to be named.  New species published in 2020 include Sciadophyllum zarucchii, named in honor of Jim Zarucchi, who worked at the Missouri Botanical Garden from 1983 until his untimely passing in 2019. He collected extensively in Colombia early in his career, where he made the original collection. Zarucchi was senior author on the Checklist of the Vascular Plants of Peru and Editorial Manager for the Flora of North America., among other things. He was held in high esteem by his colleagues.

Bonus: Rediscovery of Bourreria angustifolia

Bourreria angustifolia is a small tree or shrub with “willow-like” leaves and orange fruits the size and shape of cherries. The plant was first collected by French Botanist René Capuron in May 1965 in a remote part of Madagascar and in 2002 Jim Miller, Senior Vice President of Science & Research gave it a name. But it hadn’t been seen in the wild in decades. In early 2020, Miller was able to relocate it in the wild, meaning it isn’t too late to save this species from extinction.

Catherine Martin
Public Information Officer

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