100 MAESILEACE*. [Pilularicc 



Order III.— MARSILEACE^. 



(The characters of the Order are given at p. 17.) 



Genus I.— PILULARIA,* L. 



Rhizome filiform, creeping, rooting at the nodfes. Barren fronds 

 reduced to a filiform stipes, few or clustered at the nodes. Invo- 

 lucres globose, solitary at the nodes, sessile or shortly stalked. Sori 

 2-4, each enclosed in a membranous sac or covering, which 

 apparently divides the involucre into 2 or 4 cells. In these cells are 

 two kinds of spore cases, the lower ones, or macrosporangia, 

 containing macrospores ; the upper, or microsporangia, containing 

 microspores. 



1. P. novse-zselandise, Mrk 



This hitherto uncommon little plant was described and figured by 

 Mr. Kirk in the "Transactions of the N.Z. Institute," vol. ix. p. 

 547, and the following is his description, with the terms slightly 

 altered : — 



Rootstock creeping. Leaves (fronds) solitary, 1-2 inches long, 

 erect, setaceous. Involucre globose, 2-valved, 2-ceUed, on an erect 

 stalk ^ in. long ; microsporangia numerous, pyriform, each containing 

 20-30 microspores ; macrosporangia 20-25, ovoid, macrospores 

 globose or globose-ovoid, regular, not constricted. 



Habitat. — Lakes Lyndon and Pearson, Canterbury district, at an 

 elevation of 2,000-2,800 ft. Apparently also at Whangape Lake, 

 Waikato, in the North Island. 



In general appearance this plant might be taken for a very small 

 creeping form of grass, but for its little globular involucres. 



Order IV.— SALVINIEJE. 



(The characters of the Order are given at p. 18.) 



Genus I.— AZOLLA, L. 



Plant floating, forming small red patches, consisting of pinnate 

 fronds, covered with minute imbricating leaves. Roots of simple 

 solitary threads. Stem consisting of a central cellular axis, with a 

 few spiral threads, surrounded by a circle of air-cells. Receptacles 

 very minute, of two kinds, inserted at the base of the fronds ; the 

 larger sort female, ovoid, bursting irregularly, containing a number 

 of ovoid-stalked capsules (or sporangia) each containing 1 or more 



* Lat. , Pilula, from the form of the little capsule. 



