botany

Vataireopsis amroba. A plant for treating skin diseases

The wood of the tropical tree Vataireopsis araroba produces an exudate containing anthranoids (Goa powder, chrysarobin) which was used for topical treatment of psoriasis and other skin diseases. However, today it is larger obsolete and has been replaced by the synthetically… read more

The ’typus’ between irrationality and rationality - or: the secret law of chickweed wintergreen (‘star-flower’, Trientalis europaea)

The theory of phyllotaxis, the positions of leaves on plants, describes the reciprocal 'annidation‘ of plant organs and thus the adaptation of the plant organism to itself so to speak. In this respect it… read more

Periphery and centre — indicators for inversions in plant growth

Goethe said 'that nature has no secrets that she does not somewhere present naked to the eyes of the attentive observer' (Annals of 1790). A secret in two senses, i.e. not only for our inspection but also for our understamling, is the changing shape of the organ in the… read more

Greater spearwort (Ranunculus lingua L.)

Ranunculus lingua L. is a member of the buttercup family. It has petioleless, lanceolate leaves and grows in water close to the bank and reaches a height of 1.5 m. Göbel (unpublished) and SUCHANTKE (2009) have shown that in the genus Ranunculus, with its multitude of leaf forms, the respective… read more

Nodes and internodes — on Goethe’s concept of the spiral tendency

Starting from the interesting phenomenon of biastrepsis (‘Zwangsdrehung’), the helical twisting of shoots, in which the rhythm of node and internode formation in the plant shoot deviates from a kind of continuum of both elements, we discuss the question of the eonditions… read more

Evolutionary morphology a typological study of the development of form

The development of the inflorescence of Digitale lutea is described in detail from the formation of the primordium on the apex to the opening of the mature inflorescence and is documented by drawings of illuminated, complete preparations of the different… read more

On the behaviour of the leaf base of leaves in the vicinity to the blossoms of the genera Ranzmculus and Adonis

In the family Ranunculaceae we sometimes find transitional forms between the usually distinct leaf organs. The last leaves before the inflorescences in the leaf successions of Ranunculus acris (meadow buttercup), Ranzmculus… read more

Traces of Chronos in the root region

Close investigation of rhythmic geniculation in root systems reveals cyclic processes of generation. Distinct roots repeatedly cease and are succeedecl by lateral ones. At a longer or shorter time before such a growth interruption takes place, the direction of growth changes more or less suddenly… read more

The secret of candelabra algae (Characeae)

Candelabra algae (Characeae) belong to the most endangered fresh water plants. In deep lakes they need very clear water, poor in nutrients. In shallow water regular mechanical disturbances are necessary to protect their existence because Characeae are pioneering vegetation in such places. This… read more

Clubmosses, grape-ferns and Adder’s-tongue ferns

The clubmosses (Lycopodiaceae), grape-ferns (Botrychium) and Adder’s-tongue ferns (Op/aioglossum) are rclatively rare groups of pteridophytes in the European flora. Here we help to analyze the different species in the field as well as to grasp the obvious coherence of these differences.… read more