CHARACTERS OF TRIBES AND GENERA. 
Receptacles more or less elevated. IJndusium calyciform, 
semi-calyciform or lateral (scale like), or absent or repre- 
. sented by numerous articulate hairs. 
Oss.—The plants constituting this tribe (together with 
those of the genus Dicksonia as here restricted) are truly 
the giants of the Fern race, their erect arboreous stems 
often attaining the height of 50 or more feet, and having a 
crown of decompound (rarely simple or simply pinnate) 
. fronds, sometimes 20 feet in length, the bases of their stipes 
being either articulated with the stem and, when mature, 
separating at the articulation, the point of attachment 
being afterwards indicated by scars of an oblong rhomboid 
a 
ER 
form, spirally arranged round the stem; or more or less ` 
of the lower part of the stipes remain permanent and 
become indurated, forming part of the solid structure of 
_ the stem, which is often much increased in thickness by — 
` the production of numerous outgrowing aerial, wiry, black 
roots, forming a coating from a few inches to a foot in 
thickness, 
The species are widely distributed, chiefly within or near - 
the tropics, the number being nearly equal in the old and 
new worlds. They love shade and solitude, and in humid 
regions within the tropics are found at elevations of from 
3,000 to 6,000 feet, often in ravines. In Sikkim, Hima- 
laya, the tribe is represented by eight or nine species, all 
| are distributed throughout the islands of the Pacific Ocean, 
* their southernmost limit being Tasmania, New Zealand, 
. and Norfolk Island, where they grow at a lower elevation 
than within the tropies. Also several new species have 
recently been discovered in the Bellenden Ker range of ` 
; mountains, Queensland. 
MSS : SH 
_ of which are to be found within three miles of Rungbee. - 
_ The stems often branch into many crowns. About a dozen 
