Philcoxia minensis
| Philcoxia minensis | ||||||||||||
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| Philcoxia minensis | ||||||||||||
| VCSouza & Giul. |
Philcoxia minensis is a plant from the family of plantain plants that occurs exclusively in Brazil. It was first described in the year 2000 on the basis of a single collection in 1981. Recent research has shown that it is carnivorous .
description
Philcoxia minensis is presumably a perennial herbaceous plant and reaches a height of between 10 and 26 centimeters.
The roots are not or weakly branched, gnarled and orange, the horizontal, unbranched rhizome is 0.5 to 5 centimeters long and 0.25 centimeters thick, wiry, hairless, initially white, later a dark orange.
At the tip of the root and along the rhizome, the plants form upright, tuber-like stems that remain completely underground and reach a length of 2 to 5 millimeters. There are five to ten leaves arranged irregularly in a rosette, the petioles are mostly underground, so that the leaf blades come to rest on the ground. Occasionally the rosette also arises directly from the rhizome, then it is composed of one to six alternately arranged leaves, the tissue of the petioles is difficult to distinguish from that of the rhizome, from the stems they reach lengths of 0.5 to 3 centimeters , on the rhizome 0.1 to 2 centimeters.
The leaves are ganzrandigen gestielt shield-like manner and rounded to narrow kidney-shaped, the spreading have a diameter of 1.5 millimeters, the petioles are 14 to 24 millimeters long, its underside is hairless. The young leaves are completely subterranean and curled up like a snail while they are growing and only unroll during this period ( circinate vernation ). This type of leaf growth is in angiosperms extremely rare and almost exclusively found in carnivorous plants. Only the ripe leaves break through the surface of the earth and then unfold the longitudinally folded leaves.
On the upper side, the leaves are covered with stalked glands that secrete a sticky secretion. Upon closer inspection, numerous trapped nematodes were found on the leaf surface. However, initial tests did not reveal any evidence of the excretion of digestive enzymes , so there is no carnivory in the classic sense. Researchers at the University of Campinas in the Brazilian state of São Paulo found in an experiment that the plant absorbs nutrients from the prey. For this purpose, the nematodes used were marked with nitrogen 15, an isotope of the gas, which was then contained in the newly grown leaves.
The upright inflorescence is simple or branched, becomes 17 to 21 centimeters high and is covered with glands in the upper part. The bracts are ovate to triangular, around 1.5 millimeters long and 0.5 millimeters wide. The flower stalks are almost upright, 11 to 27 millimeters long and at the tip are covered with stalked glands that secrete a sticky secretion. These glands are also found on the ovate-lanceolate and pointed sepals that are 1 to 1.5 millimeters long and around 0.5 millimeters wide. The pale blue crown has a flower tube around 4 millimeters long, the flower lobes are circular to wide, inverted ovoid, the upper one is about 2 millimeters long, the lower 3. The stamen is 0.6 to 0.7 millimeters long and hairless, the anthers 0.5 millimeters long and elliptical. The ovary is approximately round, around 0.8 millimeters long, the stylus around 2 millimeters long and, conversely, conical. The approximately round capsule fruit has a diameter of 2.5 millimeters.
distribution
The species is endemic to the Serra do Cabral in the Brazilian state of Minas Gerais , where it grows in open spots with pure silica sand soils.
Botanical history
As part of the first description of the genus on the basis of the later Philcoxia bahiensis , research brought to light another herbarium specimen collected as early as 1981. The specimen was in poor condition and without precise location information, but could be identified as a second species of the genus and was described in 2000 together with the genus and two other species. The species epithet refers to the state of Minas Gerais , home of the species. Efforts to rediscover the species were crowned with success in 2007, studies on living specimens enriched knowledge of both the species and the genus.
proof
- Peter W. Fritsch, Frank Almeda, Angela B. Martins, Boni C. Cruz, D. Estes: Rediscovery and Phylogenetic Placement of Philcoxia minensis (Plantaginaceae), with a Test of Carnivory. In: Proceedings of the California Academy of Sciences. Fourth Series 4, Vol. 58, No. 21, 2007, ISSN 0068-547X , pp. 447-467.
- Peter Taylor, Vinicius C. Souza, Ana M. Giulietti, Raymond M. Harley: Philcoxia: a new genus of Scrophulariaceae with three new species from eastern Brazil. In: Kew Bulletin. Vol. 55, No. 1, 2000, ISSN 0075-5974 , pp. 155-163, JSTOR 4117770 .
Sources and Notes
- ↑ Image of the glands with a scanning electron microscope. (pdf; 114 kB) In: Proceedings of the National Academy of Sciences of the United States of America. Retrieved January 10, 2012 .
- ↑ a b c Plant eats worms over underground leaves. Curious plant. In: Spiegel Online. Spiegel Online GmbH, January 10, 2012, accessed on January 10, 2012 .
- ↑ a b Caio G. Pereiraa, Daniela P. Almenara, Carlos E. Winter, Peter W. Fritsch, Hans Lambers, Rafael S. Oliveira: Underground leaves of philcoxia trap and digest nematodes. In: Proceedings of the National Academy of Sciences . January 9, 2011, accessed January 10, 2012 .