28 Selaginellaceae; Isoetaceae; Ophioglossaceae 



pidate, rounded at base, appressed; spikes dorsiventral, 2.5-3 Reported to occur in Honshu (Hachijo Isl. in Izu Prov.); 



mm. wide, the bracts of upper plane larger, obliquely spread- rare. Bonins, Formosa, and Philippines. 



ing, broadly deltoid-lanceolate, about 2 mm. long, acuminate. 



Fam. 5. ISOETACEAE Mizu-nira Ka Quillwort Family 



Small grasslike or sedgelike perennial herbs, aquatic or of wet places; stem a short thick cormlike axis becoming grooved or 

 lobed with age; leaves tufted, linear, with septate air-canals, with 1 central and often 4 or more peripheral vascular bundles, the 

 leaf-base spoon-shaped with a small persistent ligule inside above the cavity; sporangia in the cavity at base of the leaves, 

 covered with a velum, of two kinds, the megasporangia usually on the outer leaves, the microsporangia on inner ones; 



megaspores tetrahedral, variously sculptured or spined. One genus, of about 60 widely distributed mostly temperate species, 



absent or rare in the Tropics. 



1. ISOETES L. Mizu-nira Zoku 



Characters of the family. 



lA. Megaspores (under a lens) deeply and subequally alveolate; corms 3-lobed at base; leaves 20-100 cm. long; velum absent; slovirly run- 

 ning water of streams and ditches 1.1. japonica 



IB. Megaspores densely spiny all over; corms 2-lobed at base; leaves 5-20 cm. long; velum orbicular to elliptic; shallow water of lakes and 

 ponds 2. /. asiatica 



1. Isoetes japonica A. Br. /. edulis Sieb. ex Miq. var. asiatica Makino Hime-mizu-nira. Small dark green 



Mizu-nira. Aquatic perennial herb; corms 3-lobed at aquatic herb; corms 5-15 mm. across, 2-lobed at base, densely 

 base, 1-5 cm. across, densely rooting on inner side of the lobes; rooting on inner side of the lobes; leaves 10-30, tufted, erect or 

 leaves tufted, many, slender, usually 20-100 cm. long, 2-5 mm. ascending, subulate, 5-20 cm. long, 1.5-2.5 mm. wide near the 

 wide at base, gradually narrowed to an obtusish tip, bright middle, gradually narrowed to an obtusish tip, subterete, with 

 green, subterete in transverse section, the phyllopodia white, a narrow flat face inside, the phyllopodia deltoid, 4-7 mm. 

 nearly square to ovate, 4-15 mm. long, 5-12 mm. wide, thinly long, 5-10 mm. wide, closely imbricate, membranous on mar- 

 membranous on margin, closely imbricate; velum absent; lig- gin, white; velum orbicular to elliptic with a suborbicular to 

 ule thinly membranous, cordate-deltoid, 3-8 mm. long, attenu- elliptic opening at base extending to the middle; ligule cordate- 

 ate-acuminate; megaspores white, globose, with 3 commissures suborbicular or broadly cordate; megaspores white, globose, 



in one hemisphere, deeply and subregularly alveolate. marked in one hemisphere with 3 commissures, densely spiny. 



Slowly running water of streams and ditches; Honshu, Shi- Shallow water of lakes and ponds; Hokkaido, Honshu 



koku, Kyushu; rather rare. Korea. (centr. and n. distr.) ; rare. s. Sakhalin. 



2. Isoetes asiatica (Makino) Makino. /. echinospora 



Fam. 6. OPHIOGLOSSACEAE Hana-yasuri Ka Grapefern Family 



Mostly terrestrial (rarely epiphytic) scaleless herbs with short fleshy stems; leaves solitary or few, straight or bent, with a 

 sterile foliar segment at base and an apical spicate or paniculate nonfoliar fertile part; sporangia bivalvate, relatively large, 

 without an annulus. Four genera, with about 90 species, of wide distribution. 



lA. Sporangia connate, forming a simple spike; foliar (sterile) leaf simple, entire or forked, with reticulate veins 1. Ophioglossutn 



IB. Sporangia free, in panicles; foliar (sterile) leaf often much dissected and toothed, with free veins 2. Botrychium 



1, OPHIOGLOSSUM L. Hana-yasuri Zoku 



Rhizomes erect, fleshy, sometimes tuberous; sterile and fertile leaves arising from a common stipe, the sterile foliar leaf simple 

 or sometimes forked at the tip, entire, reticulately veined, the fertile spike terminal, simple, pedunculate; sporangia marginal, 

 coalescent in 2 ranks, transversely dehiscent. About 30 species, of wide distribution in both hemispheres. 



lA. Epiphytic on tree-trunks, evergreen, with solitary or paired fertile spikes on upper side of an elongate entire or forked ribbonlike 



sterile frond 1. 0. pendulum 



1 B. Terrestrial, with a solitary terminal fertile spike and a lower simple, entire sterile blade, the latter sometimes much reduced or absent. 

 2A. Sterile blade present; stipes 1-3 together. 



3A. Sterile blade broadly linear to oblong or navicular, narrowly cuneate at base; exospore with rough reticulation 2. 0. thermale 



3B. Sterile blade ovate, elliptic, or nearly orbicular. 



4A. Sterile blade usually distinctly petiolate; exospore with rough reticulation 3. 0. petiolatum 



4B. Sterile blade sessile or short-petiolate; exospore with fine reticulations and the spores apparently smooth under magnification. 



4. 0. vulgatum 

 2B. Sterile blade absent; stipes 5-7 together 5. 0. liawamurae 



1. Ophioglossum pendulum L. Ophioderma pendulum ribbonlike, 30-80 cm. long, 1.5-3 cm. wide, obtuse to rounded 



(L.) Presl KoBU-RAN. Evergreen pendulous rhizomatous at apex, slightly narrowed toward the base, flat, unlobed or 



epiphyte; sterile blades tufted, green, rather fleshy, linear to more often 1 or 2 times forked at tip, entire or subentire, mar- 



