L* Pterostyh*. ORCHIDAGEAE. 1'47 



middle, channelled around the tip ; lamina concave in the vicinity of the anther, else- 

 where convex, traversed in its anterior-half by 2 principal somewhat beaded central 

 raised lines and 2 secondary parallel ones all terminating in a conspicuous reddish-brown 

 bilobed glandular process near the apex (figs. 1,3, ap.), posteriorly a central reddish- 

 brown " guide-line " (not raised) ending below the rostellum with 2 shorter and similar 

 lines on either side of it. Column produced laterally and posteriorly into membranous 

 glandular toothed or fimbriate wings over the back of the anther. 



Mount Compass ; Myponga ; also all the Eastern States and Tasmania. Dec. -Jan. 



19. PTEROSTYLIS, R. Br. 



(Greek pteron, a wing ; stylos, column.) 



Dorsal sepal concave, incurved, its lateral margins dovetailed into the petals so as to 

 form a hood or galea (PL 9, ii., fig. 11., h) over the column. Lateral sepals more or less 

 united into a lower lip (ii., fig. 11, 1.1.) ; the latter recurved, erect in front of the galea or 

 reflexed against the ovary, adnate to the foot of the column, the ends frequently tapering 

 into long fine points. The labellum attached by a movable, often irritable claw or 

 hinge, to the projecting foot of the column (fig. 11., I.) ; ovate, oblong, linear, lanceolate 

 or filiform ; sometimes furnished with long hairs ; commonly bearing at its base an 

 appendage (figs. 6, 7, ap.) short and obtuse or linear, semicircularly curved and penicillate. 

 Column elongated, following the curve of the galea, its dorsum more or less adnate to the 

 latter ; its upper part with hatchet-shaped wings (figs. 8, 9, w.) on either side of the ros- 

 tellum ; sometimes narrowly winged below ; its base produced into a horizontal foot. 

 Anther 2-celled, inclined over the rostellum, with a movable attachment to the back of 

 the clinandrium, pointless. Pollinia 4, a pair in each cell, powdery, elongated, free. 

 Stigma bilobed (figs. 8, 9, st.), prominent, situated at or near the middle of the column, 

 usually ovate or elliptical. Rostellum (figs. 8, 10, r.) much higher up on the anterior 

 margin of the clinandrium, just below the pollinia but unconnected with them, its borders 

 involute so as to form a split tube communicating with the apex of stigma. Caudicle 

 and viscid disk absent. — Terrestrial herbs with small rounded naked underground tubers. 

 Leaves frequently in a radical rosette and more or less ovate, but often cauline and linear 

 or lanceolate, occasionally crowded at the base and passing into stem-leaves or bracts, 

 very rarely reduced to bracts at the time of flowering and developing at a later stage as 

 rosettes or tufts ; the non -flowering plants of all species probably represented by one 

 of the latter. Flowers usually green, sometimes with rufous tints, commonly solitary but 

 sometimes several in a raceme. Popularly called Green-hoods. 



Of the 55 known species no less than 43 are inhabitants of Australia. Of these latter 

 3 extend to New Caledonia and 4 to New Zealand, the rest being endemic. The Dominion 

 has 8 endemic species of its own and New Caledonia 2 ; 2 more are repor ed from New 

 Guinea. 



Section 1. 



Lower lip erect ; the lobes or their points embracing the 

 galea ; flowers solitary, very rarely multiple. 

 Leaves in a radical rosette at base of scape ; more or 

 less ovate ; no stem-leaves, except sheathing bracts ; 

 flower solitary. 



Labellum bifid at tip ; galea less than 2 cm. long P. concinna 1. 



Labellum entire at the tip. 



Points of sepals short, not exceeding galea. 



Flower erect ; labellum twisted, hardly recurved ; 



galea more than 2| cm. long ■'._'. P. curta 2. 



Flower nodding ; labellum not twisted, much 



recurved ; galea not exceeding 2 cm. .......... P. nutans 3. 



Points of sepals long and fine, much exceeding galea ; 

 galea less than 2 cm. long. 

 Lob;S of lower lip separated by broad sinus, with 



inflexed tooth between them P. nana 4. 



Lobes of lower lip separated by acute sinus, with- 

 out inflexed tooth. 

 Labellum linear-oblong, tip very blunt ; stem- 

 bracts very large, conspicuous, leaf -like P. Vereenae 5. 



Labellum ovate ; stem-bracts inconspicuous, 



narrow, closely sheathing P. pedunculata 6. 



Leaves crowded at base of scape, passing gradually into 

 stem-leaves or bracts. Galea at least 3 cm. long. 

 Lohes of lower lip with very short points not exceeding 

 galea ; tip of galea very short, abruptly decurved (in 

 living plant) ; leaves sessile or almost so P. cucullata 7. 



