324 



Orchidaceae 



5B. Anther-Iocules widely separate; dorsal sepal broadly ovate, 6-8 mm. long; spur scarcely narrowed toward the obtuse apex; 



bracts broadly lanceolate 4. P. okftboi 



4B. Flowers bright green or pale green, sometimes yellowish green. 



6A. Petals obliquely ovate, strongly dilated in lower half, membranous, abruptly contracted in the upper half and not at all or 

 only slightly thickened and darkened when dry; anther-locules widely divergent. 



7A. Larger leaves 2, nearly radical, elliptic to oblong, spreading, lustrous 5. P. fiorenti 



7B. Larger leaves 1 to 3, alternate, on the lower part of stem, broadly linear to narrowly oblong, ascending to spreading. 

 8A. Sepals submembranous, the dorsal narrowly triangular-ovate, the lateral ones linear-lanceolate; petals abruptly narrowed 



and elongate at tip; leaves usually spreading, clasping at base 6. P. ophrydioides 



8B. Sepals slightly thickened, the dorsal ovate to broadly so, the lateral ones lanceolate; petals short, obtuse; leaves usually 



ascending, scarcely clasping at base 7. P. mandarinorum 



6B. Petals narrowly oblong, slightly oblique, scarcely or only slightly dilated on lower margin, hardly narrowed to the tip, ob- 

 tuse, about equally thickened throughout, often darkened when dry; anther-locules approximate. 

 9A. Lateral sepals narrowly oblong, scarcely narowed at tip. 



lOA. Bracts papillose on margin; leaves gradually reduced in those above; flowers greenish white, rather large. . . 8. P. minor 



lOB. Bracts smooth; leaves abruptly reduced in those above; flowers yellowish green, rather small 9. P. tipuloides 



9B. Lateral sepals obliquely ovate, somewhat dilated on lower margins, gradually and slighdy narrowed at tip; leaves grad- 

 ually reduced in those above; bracts smooth 10. P. sachalincnsis 



2B. Leaves several, gradually smaller above. 



IIA. Dorsal sepal navicular; leaves narrowly oblong, 4-7 cm. wide; flowers white, with a thick spur 3-4 cm. long. . . 11. P. japonica 

 IIB. Dorsal sepal flat; leaves linear-oblong or broadly linear, sometimes narrowly oblong, 1-2.5 cm. wide; spur 5-12 mm. long. 



12A. Flowers white, the spur longer than the sepals 12. P. hologlottis 



12B. Flowers yellowish green, the spur about as long as the sepals 13. P. hyperborea 



1. Platanthera chorisiana (Cham.) Reichenb. f. Habe- 

 naria chorisiana Cham.; Pseudodiphyllum chorisianum 

 (Cham.) Nevski; Platanthera matsudae Makino; Platanthera 



ditmariana Komar. Takane-tombo. Small green herb 



with slender, slightly thickened roots; stems 8-15 cm. long 

 (to 40 cm. long in var. data Finet) ; leaves 2, approximate, on 

 the lower part of stems, elliptic to broadly so, or nearly orbicu- 

 lar, 2-6 cm. long, 2-5 cm. wide, rounded to mucronate at apex, 

 abrupdy narrowed at base; scalelike leaves few, linear-lanceo- 

 late; racemes 2-10 cm. long, many to rather few-flowered; 

 bracts as long as to slightly longer than the flowers, rarely 

 shorter, linear, broadened at base; flowers minute, green; 

 sepals nearly equal, oblong to elliptic, rounded at apex, 1- 

 nerved, about 2 mm. long, the lateral sepals spreading, slightly 

 oblique; petals ovate to broadly so, slightly shorter than the 

 sepals; lip ovate-orbicular, obtuse, as long as the sepals, some- 

 what thickened; spur 1-1.3 mm. long, slighdy incurved and 



thickened above, obtuse. July-Sept. High mountains; 



Hokkaido, Honshu (centr. and n. distr.); rare. Along 



Bering Sea, Kamchatka, Kuriles, and Sakhalin. 



2. Platanthera brevicalcarata Hayata. P. ya\umon- 



tana Masam. Niitaka-chidori, Tsukushi-chidori. Small 



herb with somewhat thickened, elongate roots; stems 10-15 

 cm. long; leaves 1-2, nearly radical, oblong to elliptic, 2.5-4 

 cm. long, 1.5-2 cm. wide, rounded at apex, abruptly narrowed 

 at base; scalelike leaves 1-3, rather large, broadly lanceolate, 

 acute, ascending; racemes 2-5 cm. long, 5- to 20-flowered; 

 bracts lanceolate, acute, 4-7 mm. long; flowers greenish white; 

 sepals white, nearly equal, 1-nerved, narrowly oblong, the 

 dorsal sepal about 3 mm. long, the lateral sepals about 4 mm. 

 long, obtuse, spreading; petals rather thick, broadly semi-ovate, 

 about 3 mm. long, subobtuse, erect, forming a hood with the 

 dorsal sepal; lip oblong-ligulate, somewhat carnose, obtuse, 

 3.5-4 mm. long; spur 2-3 mm. long, slighdy curved, thick- 

 ened at tip, obmse. July. High mountains; Kyushu 



(Mount Kirishima and high mountains of Yakushima) ; rare. 

 Formosa. 



3. Platanthera metabifolia F. Maekawa. P. chlorantha 

 sensu auct. Japon., non Cust.; P. bifolia sensu auct. Japon., non 

 L. C. Rich. Ezo-CHiDORi, Futaba-tsure-sagi. Roots 



somewhat fusiform-thickened; stems 20-50 cm. long; leaves 2, 

 radical, oblong to elliptic, 8-15 cm. long, 3-5 cm. wide, obtuse, 

 narrowed to base; racemes 8-16 cm. long, rather densely 

 flowered, the bracts lanceolate; flowers white; dorsal sepal 

 ovate to ovate-elliptic, 5.5-6 mm. long, the lateral sepals about 

 8 mm. long, broadly lanceolate, obtuse, spreading; petals 

 broadly lanceolate, erect, rather thick, obtuse, slightly shorter 

 than the sepals, forming a hood with the dorsal sepal; lip 

 broadly linear, 1-1.3 cm. long, subcarnose, obtuse; spur 2-2.7 



cm. long, gradually narrowed toward the obtuse apex. July 



-Aug. Hokkaido. Kuriles and Sakhalin. 



4. Platanthera okuboi Makino. Hachijo-tsure-sagi. 

 Roots fusiform; stems 20-45 cm. long; leaves 1-2, nearly 

 radical, oblong to narrowly so, 10-20 cm. long, 3-6 cm. wide, 

 obtuse, narrowed at base; scalelike leaves rather large, erect, 

 broadly lanceolate, 2-6 cm. long; racemes rather densely 

 many-flowered, 5-10 cm. long; bracts broadly lanceolate, 15- 

 25 mm. long; flowers white to slighdy green; dorsal sepal 

 broadly ovate, obtuse, 5-nerved, 6-8 mm. long, the lateral 

 sepals broadly lanceolate, 8-10 mm. long, obtuse, 3- to 5- 

 nerved; petals erect, shorter than the dorsal sepal, slighdy 

 thickened, oblique, narrowly ovate, 3-nerved, about 6 mm. 

 long; lip broadly linear, 10-13 mm. long, obtuse; spur 2.5-3 

 cm. long. May-June. Honshu (Izu Isls.). 



5. Platanthera fiorenti Fr. & Sav. P. listeroides Takeda 



JiMBAi-so. Roots elongate; stems 20-40 cm. long, rather 



slender; leaves 2, radical, oblong to elliptic, 5-12 cm. long, 3-5 

 cm. wide, obtuse to abruptly acute, lustrous, abruptly nar- 

 rowed to base, somewhat spreading, the upper leaves small, sev- 

 eral, ascending, loose, broadly lanceolate, 5-10 mm. long, 

 acute; racemes rather loosely 5- to 10-flowered; bracts spread- 

 ing; flowers pale green; dorsal sepal ovate to ovate-elliptic, 3- 

 nerved, obtuse, 5-6.5 mm. long, the lateral sepals falcate, lance- 

 olate, 3-nerved, obtuse, 7-8 mm. long, reflexed; petals deltoid- 

 ovate, about 7 mm. long, slightly shorter than the median 

 sepal, oblique, abruptly narrowed at tip, only slightly thick- 

 ened at apex, 2-nerved; lip broadly linear, obtuse, 7-10 mm. 

 long; spur 1.5-2 cm. long, incurved, gradually narrowed 



toward the apex; rostellum broad. Aug.-Sept. Woods in 



mountains; Honshu, Shikoku, Kyushu; rather rare. 



