Wilson, H.D.; Garnock-Jones, P. J. 1983: Taxonomic notes on Stewart Island Ranunculus including two new species. New Zealand Journal of Botany 21: 341–345.
Details
Wilson, H.D.; Garnock-Jones, P. J. 1983: Taxonomic notes on Stewart Island Ranunculus including two new species. New Zealand Journal of Botany 21: 341–345.
Article
Descriptions
Rosettes single or forming small patches, appressed to the ground in exposed grassland but up to 5 cm tall in shelter of rocks. Leaves broad-ovate to deltoid, c. 9-14 × 9-14 mm, dark green, simple and crenately lobed or toothed, or cut to about halfway into 3 main lobes, rather thick and stiff, covered in pale buff hairs. Petioles 15-40 mm long, hairy, dark-mottled, with broad, sheathing, scarious, ciliate bases. Peduncle 2-4 cm long, stout, decumbent or ascending, dark-mottled or purplish throughout, hairy, bearing 1-2 simple narrow bracts near base. Flowers solitary, 15-20 mm diam.; sepals 5, caducous, green-margined, dark brown or sometimes almost black beneath; petals 5-(7), rather narrow, 7-10 × 3-4 mm, glossy yellow above but often blotched with orange-brown, dark brown beneath; nectary near base of petal, covered by a narrow oblong scale; stamens 15-20; receptacle sparsely hairy. Achenes 4-(6), blotched with very dark brown, c. 4-5 mm long; body ellipsoid, c. 2-2.5 × 1.5-2 mm; beak slender, barely curved, c. 2-2.5 mm long.
Herba rosulata a R. kirkii Petrie differt foliis crassis, trilobatis sed haud ternatis; floribus solitariis, grandioribus, nectario basali; acheniis angustioribus, rostris longioribus; a R. folioso Kirk differt floribus solitariis; nectario basali; acheniis paucis, majoribus, rostris longioribus.
Rosette herb about 8-10 cm diam., or forming compact patches up to 30 cm diam. by sympodial growth. Rhizome stout, 4-8 mm diam., loosely fibrous from the remains of sheathing petiolar bases and bearing abundant long fleshy roots c. 1.5 mm diam. Lamina deltoid to orbicular or sub-reniform, 2-3-(4) cm diam., rather thick and firm, glossy bright green above, paler but no less glossy beneath, divided about three-quarter-way into three 3-5- lobed segments, sparsely hairy with penicillate tuft at tip of each lobe. Petiole 1.5-3 cm long, cobwebby on the short, broad, sheathing base, grooved on adaxial surface. Peduncle without bracts, green, often purple-stained at base, clad in fine, cobwebby hairs, very short in flower but elongating to 3-5 cm in fruit, becoming broader upwards. Flowers solitary, 25-30 mm diam.; sepals 5, c. 15 mm long, often emarginate at tips, greenish yellow, finely hairy beneath, almost glabrous above; petals 5, barely or not exceeding sepals, c. 10-12 × 6-8 mm, bright yellow but green in basal third, the base abruptly narrowed; nectary of 3 simple pits per petal, the central one largest; receptacle almost glabrous, pale yellow-green. Fruiting head compact, globose to ovoid, c. 12 mm diam.; achenes numerous, c. 5 mm long; body bulbous, 1.5—2 mm diam.; beak straight and tapering, c. 3 mm long.
Herba rosulata a R. pingui Hook. f. differt foliis profundius divisis, segmentis angustioribus; scapo arachnoideo; petalis quinque, latis, vix rigidis; nectariis tribus; achenii rostro corpore longiore; a R. sericophyllo Hook. differt pubescentia minus densa; foliis minus divisis, segmentis latioribus; scapo basi gradatim angustato; floribus 3 cm brevioribus, petalis sepala aequantibus vel vix superantibus.
Identification keys
KEY TO THE WILD BUTTERCUPS OF STEWART ISLAND*
1
Petals white; leaves peltate, crenate
Petals yellow or flowers apetalous; leaves neither peltate nor crenate
4
Stems decumbent, rooting at nodes, but becoming erect in flowering portions; pedicels furrowed
Stems erect or sprawling but never rooting at nodes, often very short; pedicels not furrowed
7
Stems (30)-60-100 cm tall in flower; flowers >20 mm diam.; achenes 30-50 per head, strongly flattened, margins thickened, beak hooked, 0.5 mm
Stems <30 cm tall in flower; flowers 12-15 mm diam.; achenes 10-25 per head, rounded, margins not thickened, beak straight or slightly curved, 1.5-2 mm
8
Plant with rooting stolons and erect furrowed flowering stems 10-60 cm tall
Plant tufted, lacking rooting stolons; flowering stems erect or sprawling, unfurrowed, <10 cm tall
10
Leaves stiff and brittle with sparse stiff hairs across lamina; flowers and fruiting heads subsessile, the scapes <1 cm tall; achenes brick red, beak hooked, < 1 mm long
Leaves flexible with soft hairs chiefly concentrated into penicillate tufts at segment tips; flowers and fruiting heads distinctly stalked, the scapes at least 2 cm tall; achenes brown or greenish, beak almost straight, at least 3 mm long
11
Nectary very near base of petal; achenes 4-6 per head, 4-5 mm long including the 2-2.5 mm more or less straight beak
Nectary about 1/3 petal-length from base of petal; achenes 30-60 per head, 2.5-4 mm long including the 0.5-1 mm distinctly curved beak
12
Leaves pinnate; plant tufted
Leaves ternate to palmate or ternatifid to palmatifid; rosettes linked by creeping stolons or slender rhizomes
13
Leaves firm-textured, leaflets elliptical; flowers and fruiting heads usually sessile or subsessile; achene beak 0.5-1 mm, shorter than achene body
Leaves thin-textured, leaflets narrow-lanceolate; flowers and fruiting heads distinctly stalked; achene beak 1.5-2 mm, longer than achene body
Reproduced with permission from New Zealand Journal of Botany and The Royal Society of New Zealand Te Apārangi.
Cited scientific names
Metadata
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reference
Names_Plants