Question

A saprophytic bryophyte found in the Himalayas is
A. Sphagnum
B. Marchantia
C. Parella
D. Buxbaumia

Answer 1

Hint: Buxbaumia is a genus of twelve species of moss (Bryophyta). Plants of Buxbaumia have a much-reduced gametophyte, bearing a sporophyte that is enormous by comparison. In most mosses, the gametophyte stage of the life cycle is both green and leafy and is substantially larger than the spore-producing stage.

Complete step by step answer: Buxbaumia plants are dioicous, with separate plants producing the male and female organs. Male plants develop only one microscopic leaf around each antheridium, and female plants produce just three or four tiny colourless leaves around each archegonium. Because of its small size, the gametophyte stage is not generally noticed until the stalked sporangium develops, and is locatable principally because the sporangium grows upon and above the tiny gametophyte. Buxbaumia does not produce abundant chlorophyll and is saprophytic. Some of its nutritional needs may be met by fungi that grow within the plant.
Species of Buxbaumia may be found across much of the temperate to subarctic regions of the Northern Hemisphere like the Himalayas in India, as well as colder regions of Australia and New Zealand.
The moss is an annual or biennial plant and grows in disturbed habitats or as a pioneer species. The plants grow on decaying wood, rock outcrops, or directly on the soil. They do not grow regularly or reliably at given locations and frequently disappear from places where they have previously been found. Sporophyte stages begin their development in the autumn and are green through the winter months.
Hence, the correct answer is option D.

Note: Unlike these other mosses, the gametophyte of Buxbaumia is microscopic, colourless, stemless and nearly leafless. It consists exclusively of thread-like protonemata for most of its existence, resembling a thin green-black felt on the surface where it grows. The sporophyte at maturity is between 4 and 11 mm tall. The spore capsule is attached at the top of the stalk and is distinctive, being asymmetric in shape and oblique in the attachment. The opening through which the spores are released is surrounded by a double peristome (diplolepidious) formed from the cell walls of disintegrated cells.