Victorian Plants. 115 



566. Spore-caselets opening by a transverse slit ... ... 567 



Spore-caselets opening by a longitudinal or vertical 

 slit 568 



567. Sterile frond solitary, often leaf-like, entire. 



Glabrous ferns, usually quite small, rarely large and then 

 epiphytal, never ramified ; spore-caselets in an often 

 terminal spike, biseriate, devoid of any ringlet ; bracteal 

 organs absent. Ophioglossum. 2134 



Sterile frond solitary, divided into segments. 



Glabrous ferns, usually rather small or even minute ; spore- 

 caselets in paniculated spikes, biseriate, devoid of any 

 ringlet ; bracteal organs absent. Botrychium. 2135 



Spore-caselets terminated by a radiating ringlet. 



Small or even minute ferns; fronds or their segments always 

 very narrow ; sterile fronds several, entire or divided 

 into segments ; fruit-masses usually on a singly terminal 

 pinnule and reaching beyond it ; pinnule beset with 

 hairlets ; spore-caselets opening by a longitudinal slit on 

 one side. Figure 132. Schizaea. 2136 



Spore-caselets surrounded by a transverse ringlet ... 569 



569. Spore-caselets two, three or few to each frond-segment. 



Ferns often tall, slender and dichotomously branched; 

 segments of the pinnules in two rows ; fruit-masses on 

 the lower side of the frond and overreached by its 

 segments ; spore-caselets opening by a longitudinal slit. 

 Figure 136. Gleichenia. 2137 



Spore-caselets crowded. 



Ferns either tall or big and then with thick fronds, or rather 

 dwarf and then with transparent fronds ; fruit-masses on 

 the lower side of dilated or much contracted frond- 

 segments, usually in large patches ; spore-caselets opening 

 by a longitudinal slit, partly surrounded by an imperfect 

 transverse ringlet. Figure 137. (Todea.) Osmuuda. 2140 



570. Arborescent ferns with tall trunks ... ... ... 571 



Ferns from dwarf to rather tall, but without any 

 arborescent trunk ... ... ... ... 573 



