HOOKER LECTURE, 1922. 235 
MARATTIACEÆ. 
This family of Eusporangiate Ferns includes the genera Angiopteris, 
Archangiopteris, Marattia, Danæa, Macroglossum, and Christensenia. In their 
thick fleshy stems, the large stipules, and in the soral characters these genera 
are in marked contrast to those already described. Marattia occurs in the 
tropics of the East and West hemispheres ; Angiopteris is widely spread 
in the Eastern tropics in Malaya, India, Ceylon, Formosa, and Tahiti. 
Angiopteris includes species with the tri-pinnate fronds 12 ft. long with 
pinnæ 4 em. broad and 30 em. long, bearing short linear sori of separate 
sporangia. In the Bornean genus Macroglossum, with fronds of the 
Angiopteris-type, the pinnæ are broader and longer and the sori contain 
more sporangia. It is noteworthy that this genus of restricted range is very 
similar in the characters of its fronds to some of the widespread Rhætic 
species assigned to Marattiopsis or Daneopsis. Certain species of Marattia 
closely resemble Angiopteris in habit, but occasionally the larger pinnæ show 
a tendency to subdivision into small segments, while in other species the 
ultimate segments are only a few millimetres in length. In Marattia the 
sporangia are united into woody capsular synangia. Archangiopteris from 
Southern China has pinnate fronds with segments like those of Danea, but 
the sori except in their greater length are like those of Angiopteris. The 
greater length of the linear sori is a character met with in fossil Maratliaceous 
fronds from Rheetic beds. Dan@a is confined to tropical America ; the 
fronds are simple or pinnate and the elongate sori extend from the midrib 
almost to the edge of the lamina. The parallel rows of sporangia are united 
into compact masses by union with them of tissue which grows up from the 
fertile lamina. Costa Rica possesses a species of Danæa with delicate and 
relatively small leaves in texture like those of a filmy fern. The genus 
Christensenia from the Philippines differs from all others in its palmate 
leaves resembling those of a Horse Chestnut and in the peculiar circular 
sori. The disposition of the main ribs recalls the habit of Matonia pectinata 
and Neocheiropteris. 
Omitting the fern-like fronds from Upper Paleozoic floras which in the 
characters of the sori appear to resemble those of existing Marattiaceæ more 
closely than the Leptosporangiate ferns, the oldest examples of fronds with 
fertile pinnæ agreeing generally in habit with Angiopteris, Macroglossum, and 
Archangiopteris are from Upper Triassic beds in Switzerland, Austria, and 
France. An excellent account of Palæozoic Ferns is given by Dr. Scott in 
the last edition of his ‘Studies in Fossil Botany’ in which he describes 
several species which reveal both in soral characters and in anatomical 
structure obvious points of contact with the Marattiaceous type. He quotes 
the genus Asterotheca as a Paleozoic fern which persisted into the Triassic 
and even Rhetic period. It is, however, in the older Mesozoic rocks that we 
LINN. JOURN, —BOTANY, VOL. XLVI, S 
