An. Australian group well adapted to life in subalpine bogs. Pt. alpina Rog. and Pt. furcata Ldl. both appear to have originated from Pt. falcata Rog. Pt. furcata has extended to New Zealand and differentiated again into two quite distinct forms.
12. Pterostylis furcata Ldl., Gen. et Spec. Orch., 1840, 390.
A compound species of 2 jordanons, one in both Australia and New Zealand and the other confined to New Zealand.
(a) Pt. furcata var. typica Hatch.
Pt. mioromega Hook. f., Fl. Nov. Zel., 1, 1853, 248.
Pt. polyphylla Col., Trans. N.Z. Inst., 22, 1890, 489.
Up to 20 cm. high. Leaves 1–8, repand or flat, lower few usually subrosulate, petiolate, the upper cauline, sessile, or all may be cauline, oblong-ovate to -lanceolate, acute, up to 4 cm. long by 15 mm. broad. Floral bract foliaceous. Flower very pale, solitary, up to 4 cm. high. Dorsal sepal acuminate, longer than the petals, the tip horizontal or recurved. Lateral sepals filiform-caudate, exceeding the galea by as much as 15 mm. Labellum linear-oblong, obtuse, recurved and slightly
Fig. 1—Pt. trullifolia var. rubella nat. size. a, column and labellum from side; b, labellum from above; c, stigma; d, lateral sepals; j, special form adapted to vegetative reproduction; k, juvenile.
Fig. 2—Pt. trullifolia var. gracilis nat. size. Dissections as for var. rubella.
Fig. 3—Pt. trullifolia var. alobula nat. size. e, labellum from above; f, stigma; g, lateral sepals; h, intermediate stage.
twisted, the midrib channelled conspicuously on either side. Column slightly inclined, stigma narrow-obovate. Column-wings with acuminate upper lobes as high as the anther. Lower lobes narrow-oblong, the inturned margins finely ciliate. As a bud, and when just opened, the flower is beautifully symmetrical, but with maturity it goes to pieces, the segments falling away in all directions, so that at a stage when most Pterostylis flowers are in their prime, this species presents an untidy appearance. Very susceptible to epharmony, changing from subrosulate to cauline with environment. The juvenile is a close rosette of 3–5, ovate, petiolate leaves.
Distribution. Australia—Tasmania, Victoria, South Australia, New South Wales, nowhere abundant. New Zealand—2, Kaitaia, R. H. Matthews; 3c, Coromandel Harbour, Jolliffe; 5, abundant in Hypolaena bogs from Rotorua to Murimotu, particularly so along the western slopes of Mount Ruapehu, Allison, Matthews, Hatch; 6, Ngaire, T. F. Cheeseman; 7, Wairarapa, W. Colenso; Chatham Islands, 12, 1886, W. Travers.
Flowers December–January, sea-level–3,000 ft. Probably windborne across the Tasman originally.
(b) Pt. furcata var. linearis Hatch var. nov.
Pt. mioromega Cheesmn. in part (not of Hook. f.).
Pt. furcata typica affinis. Differentis in parvitas; folia lineata acuminata; sepala brevissima; stigma late cordatum.
Up to 18 cm. high. Leaves 1–4, cauline, sessile, linear-lanceolate, acute, up to 6 cm. long by 1 cm. broad. Flower similar to but much smaller than the type, the lateral sepals acuminate and hardly exceeding the galea. Stigma broadly cordate. The juvenile is a close rosette of 2–4 broad-elliptic, shortly petiolate leaves.
Distribution. Endemic—5, National Park, 12, 1921, H. B. Matthews; Murimotu, D. Petrie; 12, 1944, E. D. Hatch.
Flowers December, 3,000–4,000 ft. Abundant in Hypolaena bogs, not so far found in company with the type jordanon. Probably derived from Pt. furcata typica.
Holotype in Herb. Hatch, No. 565, Murimotu, 12, 1944, E. D. Hatch. The accompanying illustration can be regarded as the hypotype of the variety.