Question

Rhynia was discovered from?
a. Rhynie chert valley
b. India
c. Pakistan
d. Bihar

Answer 1

Hint: Rhynia was first identified as a novel species by Robert Kidston and William H. Lang in 1917. The location where it developed is in the area of a silica-rich hot spring. The plants of Rhynia were herbaceous. R. major was 50 cm. in tallness and 1.5 to 6 mm in width, whereas R. gwynne-vaughani was only about 20 cm. in altitude and 1 to 3 mm in width.

Complete answer:
Rhynia, tracheophyte, produced right along with other vascular plants like Asteroxylon mackei, a possible ancestor of recent club mosses (Lycopsida), and with pre-vascular plants like Aglaophyton major, which is taken as basal to true vascular plants.

Rhynia was an uncomplicated, leafless plant with a creeping, horizontal stem (rhizome) from which the straight, aerial shoots arose. The tips of fertile shoots tire oval-shaped sporangia and the prostate, horizontal axis was held up by rhizoids, rather than true roots.

Roots were not present but at places, the rhizome was provided with a bunch of unicellular rhizoids. The aerial shoots were cylindrical and leafless with a thinning dichotomously branched system. The species is accessible only in the Rhynie chert in Aberdeenshire, Scotland.

Hence, The correct answer is option (A).

Note: In R. major the aerial shoots were simple and silky but in the case of R. gwynne-vaughanii many adventitious branches were there on the mid-air shoots and rhizome. These branches possibly help in vegetative propagation. The tip of the aerial branch typically bears a solitary terminal sporangium which is about 12 mm in height and about 4 mm in thickness.