''Lindernia intrepida'' is a species of aquatic plant that is native to central-west

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

, growing in

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a aridity, dry climate sub-type. It is located on regions that receive precipitation below Evapotranspiration#Potential evapotranspiration, potential evapotranspiration, but not as l ...

and

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

regions. It grows in shallow temporary pools on granite

inselberg An inselberg or monadnock ( ) is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In Southern Africa, a similar formation of granite is known as a koppie, an ...

s, surviving regular environmental extremes that include drastic daily changes in temperature and pH, along with extreme fluctuations in wetting and drying. It was previously known as ''Chamaegigas intrepidus'', meaning "intrepid dwarf giant", referring to the tiny plant's ability to thrive even in the desert.

Description

''Lindernia intrepida'' grows in intertwined mats, with two different leaves. One is an underwater awl-shaped leaf that is long. Two pairs of unequal length leaves float on the water, and oval-shaped. The plant grows from a small

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

growing in a combination of sand, organic debris, leaf remains, and animal dung that is deep. The flowers have two lips, and are white or pale pink with purple speckles. ''Lindernia intrepida'' is one of approximately 330 desiccant-tolerant

vascular plant Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Ti ...

s, 90% of which are found growing on inselbergs. It is one of the rare desiccant-tolerant vascular plants that is not a

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

monocotyledon Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks ...

. The basal leaves can survive complete drying for 4.5 months, with more than 50% of them reviving after receiving moisture—so the plants simply resume growing once the pools fill again after a dry spell. New floating leaves, which do not survive drying as well as the basal leaves, can reach the water surface as soon as 2–4 days after the pool refills, with flowers appearing as early as 4 days after breaking dormancy.

Taxonomy

''Lindernia intrepida'' was discovered by German botanist

Kurt Dinter Moritz Kurt Dinter (10 June 1868 – 16 December 1945) was a German botanist and explorer in South West Africa. Education and career Dinter was born in Bautzen, where he attended the Realschule. After completing his military service he joi ...

in 1909. The previous binomial name translates to "intrepid dwarf giant", referring to the small plant's ability to survive the most extreme conditions. It is considered to be a resurrection plant because it quickly revives from complete dormancy.

Habitat and distribution

The plant is native to central-west Namibia, growing in semi-arid conditions in very shallow () temporary pools in granitic rock. The pools can dry out and refill 15 to 20 times each year. The pools also go through daily extremes of temperature and pH. Water temperatures can range from between day and night, while the late afternoon water pH can be greater than 10 and morning pH less than 6. The rhizomes can also be exposed to temperatures during the 11-month dry season.

Notes

External links

IPNI Listing
{{Taxonbar, from=Q5069353 Flora of Namibia Aquatic plants Linderniaceae Monotypic Lamiales genera