Horstrissea is a monotypic genus probably related to Scaligeria (Strid 2016). Horstrissea dolinicola was descibed in 1990 (Egli et al. 1990).

Horstrissea dolinicola is listed as Critically Endangered B1ac(iv)+2ac(iv) in view of its highly restricted occurrence at only one location in Crete, with an extent of occurrence (EOO) of 4 km² and an area of occupancy (AOO) of 4 km², and the fact that extreme fluctuations have been recorded in the number of mature individuals. Grazing and trampling are significant threats to the species affecting the whole population, leading to significant limitations in the species reproductive success.

This species is only found at Mt. Ida (Psiloritis) in central Crete, at 1,400-1,500 m altitude, covering an area of approximately 7,500 m².

Population estimation studies as well as monitoring of the species is being implemented by the Mediterranean Agronomic Institute of Chania in the framework of funded projects since 2019 (Fournaraki et al. 2021, 2022). Field visits for the monitoring of the population take place twice a year, once in spring when leaves emerge at the ground level and once in summer when inflorescences appear. The number of mature individuals varies largely depending on the year, with the lowest number recorded being 1,300 and the largest 17,300 flowering individuals. This indicates that H. dolinicola, like other members of the Apiaceae family, exhibits the phenomenon of mass flowering, meaning that in some sporadic years, probably due to environmental effects, a larger amount of plants flower compared to other years. There are no data on how long the species can survive in dormancy, but it is possible that the species has an increased risk of extinction if the conditions are not right for mass flowering for several consecutive years and the dormant root does not survive this period. For this reason, we precautionarily assume that the species is exhibiting extreme fluctuations.

 Prior to the above-mentioned intensive studies it had been estimated that there were fewer than 100 mature individuals left in the wild (Egli 1995, Iatroú and Fournaraki 2017).

It is a dwarf perennial geophytic species which grows in a few limestone sinks (dolines) in a region where many sheep graze during the summer season. These sinks are seasonally flooded as they work as outlets for melting snow (spring). A great number of species endemic to the mountains of Crete grow in these limestone sinks. All the plants are very small and hug the ground, a strategy which allows them to withstand the grazing pressure of numerous herds of sheep.

Horstrissea dolinicola is mainly threatened by shepherds feeding their sheep and goats during summer when the above ground part of the plant appears. Grazing and trampling of flowering stems highly affects the reproduction of the species as shown by experiments with fenced and non-fenced areas conducted by the Mediterranean Agronomic Institute of Chania (Fournaraki et al. 2021). Road construction (some shepherds created several off-road trails with their 4×4 vehicles inside the areas of some patches) and livestock infrastructure (troughs and milking areas) were past threats to the species but this is no longer occurring due to management changes.

As a threatened and endemic species, it is protected by the Greek Law 3937/2011. It is considered one of the Top 50 Mediterranean Island Plants (UPDATE 2017) by the IUCN SSC Mediterranean Plant Specialist Group.

The plant has indirect protection as its population falls within the Natura 2000 site GR4330005 – Oros Idi (Vorizia, Geranoi, Kali Madara). In the framework of the CARE-MEDIFLORA project, a plant-micoreserve (characterised as 'Protected Natural Formation') covering an area of 8.9 hectares was established in the 'Petradolakia' site to protect part of the species population. In addition, a successful reinforcement protocol has been developed and the population has been reinforced with approximately 500 new plants.

Seeds are stored in the Seed Banks of the Mediterranean Agronomic Institute of Chania and the National and Kapodistrian University of Athens; the germination ecophysiology has been studied (Fournaraki 2010).