Poterium.] XXIV. bosaceae. 135 



flowers, but only 1 or 2, and usually imperfect, in the female flowers, witli fimbriate 

 stigmas. Some imperfect female flowers have 3 penicillate stigmas. Fruiting- 

 calyx red, unarmed. Achene subulate, coriaceous. 



SOUTH Island; Marlborough; Mount Mouatb and other mountains in the Awatere, T. K- 

 Nelson : Wairau Gorge, Rough! TraversI Fowler's Pass and Mount Captain, Amuri, T. K. Otago: 

 Mount Ida, Petrie. Mountains above Lake Harris, T. E. 3,000ft. to 4,500£t. Jan. 



The perfectly glabrous habit and compressed spineless .calyx distinguish this species from all 

 others, while the numerous stamens of the perfect male flowers and the two penicillate stigmas are 

 exactly those of Poterium, and are, I believe, unique in Acaena, to which tlie plant must clearly 

 be referred on account of the fimbriate stigmas of the perfect female flowers. 



•POTERIUM, Linn. 

 Calyx persistent, turbinate, constricted at the mouth ; lobes 4, broad, spreading, 

 imbricate in bud. Petals 0. Stamens 4-20 or more, perigynous. Disk lining the 

 calyx-tube and thickened at its mouth. Carpels 1-3 ; style terminal ; stigma peni- 

 cillate; ovule 1. Achenes 1, rarely more, enclosed in the hardened tetragonous calyx- 

 tube. Perennial herbs, with unequally pinnate leaves, stipules adnate to the petiole, 

 and terminal heads or spikes of dioecious or polygamous flowers. 



Pruiting-calyx with netted veins . . . . . . . . . . . . * P. Sanguisorba_ 



Fruiting-calyx pitted and murioate . . . . . . . . . . * P. jpolygamum. 



* P. Sanguisorba, L., Sp. PL. 994. Stems erect, 6in.-18in. high. Eadical 

 leaves 3in.-6in. long; leaflets shortly stalked, ovate, coarsely toothed. Heads with 

 the lower flowers male or hermaphrodite, upper female ; bracteoles ciliated. Stamens 

 12-20, with pendulous capillary exserted filaments. Fruiting-calyx hard, 4-angled, 

 with netted veins and 4 thin wings. — Acaena Huttonii, E. Br., ter. in Trans. N.Z.I, 

 xvi. (1883) 382. 



NORTH and SOUTH Islands : observed in Auckland, Hawke's Bay, Wellington, Nelson, 

 Canterbury, and Otago, but scarcely naturalised. Burnet. Dec, Jan. Europe, &c. 



* P. polygamum, Waldst. and Kit., PI. Bar. Hung. ii. 217, t. 198. Usually 

 more robust than the preceding species, the stems more deeply furrowed, the leaves 

 longer and more deeply toothed, heads much larger, and fruiting-calyx with 4 

 denticulate or entire wings ; the tube deeply pitted or reticulated ; ridges muricated. 



SOUTH Island ; near Lake Ellesmere and other places on the Canterbury Plains. Scarcely 

 naturalised. Central and South Europe. 



* ROSA, Linn. 

 Calyx urceolate, persistent, contracted at the mouth, at length fleshy ; lobes 5, 

 imbricate, spreading in flower, leafy. Petals 5. Stamens numerous, perigynous. 

 Disk lining the calyx-tube, thickened at the mouth. Styles subterminal. Ovaries 

 hairy, becoming bony achenes enclosed in the fleshy calyx-tube. Shrubs, erect 

 or climbing, with prickly stems, pinnate leaves with toothed leaflets and adnate 

 stipules, and terminal solitary or corymbose flowers. 



Prickles hooked, numerous, intermixed with bristles . . . . . . . . * R. rubiginosa. 



Prickles many, hooked. Setae . . . . . . . . . . . . ' R. canina. 



Prickles few. Leaves soft, rugulose . . . . . . . . . . . . * R. multiflora. 



* R. rubiginosa, L., Mant. ii. 564. An erect shrub, 4ft. -6ft. high. Stipules, 

 leaves, and sepals copiously glandular, pubescent, fragrant. Prickles on stem and 

 branchlets slender, from a linear dilated base, liooked. Leaflets at length glabrous 

 above, downy beneath, doubly serrate. Flowers 1-4. Peduncles setose. Sepals 

 elongate, pinnate, glandular. Fruit globose or ovoid, crowned with a disk. 



NORTH and SOUTH Islands : abundantly naturalised, and destructive to pasturage. Sweet- 

 briar. Oct. to Dec. Europe, &o. 



