Hladnikia
Conservation status
Data Deficient  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Apiales
Family:	Apiaceae
Genus:	Hladnikia Rchb.[2]
Species:	H. pastinacifolia
Binomial name
Hladnikia pastinacifolia Rchb.[2]
Synonyms[2]
Carum latifolium (Bluff, Nees & Schauer) Benth. & Hook.f. ex B.D.Jacks. Critamus latifolius Bluff, Nees & Schauer Falcaria latifolia (Bluff, Nees & Schauer) Koch Falcaria pastinacifolia (Rchb.) Rchb.fil. Prionitis pastinacifolia (Rchb.) Koso-Pol.

Hladnikia is a monotypic genus of flowering plants belonging to the family Apiaceae.^[3] Its sole species, Hladnikia pastinacifolia, is a Slovenian paleoendemite,^[4][5] restricted to the area of only 4 km², located in Trnovo Forest Plateau, karst plateau of Western Slovenia.^[6] German botanist Heinrich Gottlieb Ludwig Reichenbach named the genus after Carniolan botanist and founder of Ljubljana Botanical Garden Franz Hladnik.^[4][7]

Description

Hladnikia pastinacifolia is a monocarpic herbaceous perennial plant, which takes a few vegetation periods to develop into a flowering plant.^[6] Individuals, which have erect flowering stem, can reach from 15 to 30 centimetres of height.^[8] At first plant's leathery and glossy leaves are simple shaped and arranged into rosettes. Later on, as their area increases, leaves also change shape into lobate.^[6][8] Hladnikia pastinacifolia resembles well-known celery (Apium graveolens), but has thicker foliage and shorter leaf stems.^[4] The species' root is long and lignified. The plant's flower has white, heart-shaped and 1 mm long petals.^[8]

Not much is known about the plant's exact breeding system. This plant species is entomophilous and has multiple different pollinators. It is thought that outcrossing happens occasionally.^[6] The species flowering period is between Mai and July.^[4] After successful pollination seeds that don't have any special dispersal adaptation develop between the end of August and into September. A fruit is a schizocarp, which after maturing splits into two 4 mm sized mericarps,^[6] 2 mm wide.^[8]

Hladnikia pastinacifolia chromosome number is 2n = 22.^[8]

Distribution and conservation

The plant is a Slovenian paleoendemic species restricted to small area (4 km²) in Trnovski gozd. There these plants grow only on southern slopes of the plateau and two isolated areas located 9 km away on the northern slopes.^[6] As the plant species is not a habitat specialist its growing areas are various; Hladnikia pastinacifolia was found on stony grasslands, rock crevices and screes. Laboratory molecular analyses have shown that Hladnikia pastinacifolia is a Pleistocene survivor in situ.^[8]

Even though its population trend is labeled as stable by IUCN Red list, it has data deficient (DD) conservation status.^[9][1] Among mentioned threats are human intrusions and disturbance (such as recreational activities) as well as natural system modifications.^[1] The Trnovo Forest Plateau is listed as Natura 2000 site.^[9][10] Because of its small area of distribution and different threats the species is studied for possible cryopreservation.^[5][11][12]

References