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  • Under Assessment
  • Preliminary Assessed
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Rhodactina rostratispora S. Vadthanarat, O. Raspé & S. Lumyong

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Scientific name
Rhodactina rostratispora
S. Vadthanarat, O. Raspé & S. Lumyong
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Preliminary Assessed
Proposed by
Santhiti Vadthanarat
Santhiti Vadthanarat
Comments etc.
Gregory Mueller

Assessment Notes

possibly assessed under A, if data on habit loss in Cambodia and Laos can found.

Taxonomic notes

The genus contains three species namely Rhodactina rostratispora Vadthanarat, Raspé & Lumyong (2018), R. himalayensis Pegler & T.W.K. Young (1989), and R. incarnata Zhu L. Yang, Trappe & Lumyong (2006).

Rhodactina rostratispora is a small to medium-sized (1–5 cm diam.) sequestrate Boletaceae. It is different from the other two species in the genus by its basidiospores having a markedly prominent hilar appendage, with a terminal hilum; ornamentation consisting of (7)8–9 longitudinal ridges, while the other two species basidiospores have no the prominent hilar appendage. The number of ridges on the basidiospores of R. rostratispora is similar to R. incarnata [(7)8–9(10)], while R. himalayensis has a lower number of ridges [(5)6–7(8)] (Pegler and Young 1989, Yang et. al. 2006, Vadthanarat et. al. 2016).

Why suggested for a Global Red List Assessment?

Rhodactina rostratispora is one of three species in the genus, was described in 2018, based on collections from two small community forests in Ubon Ratchathani Province, Northeastern Thailand (Vadthanarat et al. 2018). At present (2020), about half of the forest where the holotype was found, has been destroyed for Cassava and rubber tree plantations. Another site has also been surrounded and slowly degraded by local people for the plantations (about 2 square kilometers remaining).
In the last 5 years, the population of this species seems to be declining due to the decrease of the areal of community forests in northeastern Thailand. Therefore, the protection of its habitat, awareness, and communications to the local people are needed.

Geographic range

The species is only recorded from three sites in northeastern Thailand, 2 from Ubon Ratchathani Province and one from Surin Province. Although not yet recorded from other countries, appropriate habitat occurs along the Mekong River in Cambodia and Laos. These regions have not been intensively surveyed for fungi. 

Population and Trends

To date, the species is only known from three sites in northeastern Thailand. Two of the sites are under severe threat in Ubon Ratchathani Province. In the last 10 years, one of the localities where the species was found has been deforested for cassava fields. Another site is being converted by local people for plantations and water reservoirs.  Wildfires in the region have destroyed more habitat.  There are now only about 2.1 square kilometers of forest remaining in the province. Habitat in Cambodia and Laos are also under threat.

Population Trend: Uncertain

Habitat and Ecology

TThe species produces subepigeal basidiomata.  To date it has only been recorded on sandy soil in open dry dipterocarp forests dominated by Dipterocarpaceae mainly Dipterocarpus tuberculatus, D. intricatus, D. obtusifolius, Shorea obtusa, with some S. siamensis, S. roxburghii, and a few of Eucalyptus sp., at elevation of near 150m.  Sporocarps have be found from June to August. It presumably forms ectomycorrhizal associations with trees of the genera Dipterocarpus and Shorea (Dipterocarpaceae).  In Thailand much the original low elevation dipterocarp forest habitat on these alluvial soils has been urbanized or converted to agricultural land. Similar habitat also occurs along the Mekong River in Cambodia and Laos.

Subtropical/Tropical Dry Forest


Habitat loss due to deforestation for agricultural effots including rice and cassava fields and rubber tree plantations has significantly reduced the amount of suitable habitat.  Wildfires in the region have destroyed more habitat.

Agro-industry farmingIncrease in fire frequency/intensity

Conservation Actions

Habitat protection is needed.

Site/area protectionResource & habitat protection

Research needed

The distribution needs to be better known. The ectomycorrhizal symbiotic partners should be identified.

Population size, distribution & trendsLife history & ecology

Use and Trade

No use known


Country occurrence

Regional Population and Trends

Country Trend Redlisted