506 ROSACEAE. [ Acaena. 
sheathing at the base, adnate to the petiole. Flowers hermaphrodite or 
unisexual, small, crowded in a terminal globose head, or (in species not 
native in New Zealand) into an interrupted spike. Calyx-tube obconic or 
turbinate, constricted at the mouth, terete or angled, naked or at length 
armed with simple or barbed spines; lobes 3-7, valvate, persistent or 
deciduous. Petals wanting. Stamens 1-10, very rarely more. Carpels 
1—2, wholly immersed in the calyx-tube ; style subterminal, short, exserted, 
dilated into a fimbriate or plumose stigma; ovule solitary, pendulous. 
Achenes solitary or rarely 2, enclosed in the hardened calyx (cupule) which 
is usually armed with subulate spines or bristles. Pericarp bony or 
membranous. 
A genus widely spread in the temperate and montane regions of South America. 
Its centre of distribution is undoubtedly in the Andean districts of Chile and Peru and 
southwards to Fuegia; but one species is found as far north as California, another in 
Mexico, and a third in the Hawaiian Islands. There is also an outlying species in South 
Africa. The antarctic circumpolar islands contain 3 or 4 species, and 3 also occur in 
Australia and Tasmania. Of the 9 species admitted in this work as natives of New 
Zealand all but 2 are endemic. One of these (4. adscendens) reaches the New Zealand 
botanical region only in Macquarie Island.- 
The publication of a complete monograph of Acaena, written by Dr. G. Bitter, 
the Director of the Bremen Botanical Gardens, which took place in 1910-11, is a matter 
of importance to all New Zealand botanists. For the first time, it has been made 
possible to study the genus as a whole, and to compare the species of this country with 
those from abroad. The writer has found it invaluable in drawing up the following 
account of the New Zealand species; and, although, through the exigencies of space, 
he has been unable to give the same detailed treatment as that afforded by Dr. Bitter, 
or, In some instances, to arrive at the same conclusions, there can only be one opinion 
as to the value of Dr. Bitter’s work as a guide for future research. 
A. Ancistrum. Spines usually 4, placed near the top of the cupule ; retrorse barbs present 
near the summit of the spine. : 
Leaves small, 1}-2$in., glabrous or nearly so, glaucescent on 
both surfaces, leaflets 9-15. Stamens 2-4. Cupule laxly 
saccate af ia 4%: 53 a: .. 1. A. saccaticupula. 
Leaves large, 24-4 in., glabrous or nearly so above, pilose beneath, 
green on both surfaces, leaflets 13-15. Stamens 4 .. .. 2. A. adscendens. 
Leaves small, 1-2 in., glaucescent on both surfaces, upper surface 
densely pilose; leaflets 11-15. Stamens 2 a a 
Leaves 13-3 in., glaucescent on both surfaces, upper surface 
nearly glabrous, but a pencil of hairs at the tip of the teeth .. 4. A. fissistipula. 
Leaves 13-4 in., silky-pilose, green or brownish-green to rubescent 
above, paler below; leaflets 11-13. Heads large, 3-11 in. 
diam. Spines purplish-red v 2 nit .. 5, A. novae-zelandiae. 
Leaves 1-3 in. long, silky-pilose, green or brownish-green above, 
paler or glaucous beneath ; leaflets 7-11. Heads 3—3 in. diam. 
Spines green or brownish-green or rubescent os .. 6. A, sanguisorbae. 
3. A. hirsutula. 
B. Microphyllae. Leaves small.  Spines usually 4, placed near the top of the cupule, 
often flexuose, sometimes absent.  Retrorse barbs few or wanting, sometimes replaced 
by long and thin flexuose reflexed hairs. 
Glabrous or sparingly pilose. Heads pedunculate, rarely sessile. 
Spines bright-red, rarely wanting, when present without 
retrorse barbs os os +. Ms .. 7. A. microphylla. 
Leaves pale whitish-glaucous. Heads usually sessile. Spines 
greenish or yellowish, furnished with reflexed flexuose hairs .. 8. 4. Buchanani. 
C. Pteracaena. Heads large.  Cupule compressed, furnished with 2 lateral wings. 
Spines on the cupule very short, without retrorse barbs. 
Perfectly glabrous. Heads brownish-green, sometimes suffused 
with red 9. A. glabra. 
