Psiadia. ] 
COMPOSITE. 
171 
Var. quinquenervia. Branches stouter. Leaves obovate, 3-4 in. 
long, subacute, entire, with two prominent ribs on each side of the 
midrib, 1 J-2 in. broad, deltoid, narrowed in the lower third into a 
distinct petiole. Heads £ in. long and broad, with 30-10 flowers in 
each. P. integerrima, var. quinquenervia, DC. P. glauca, Ayres , 
MSS. with description. (Elphegea quinquenervia, Cass. Diet. xiv. 363.) 
Var. balsa mica {DC. Prod. v. 319, as a species). Leaves obovate- 
cuneate, distinctly triplinerved, 1-1| in. broad, scarcely petioled, fur- 
nished with a few distinct acute teeth on each side in the upper half. 
Heads as large as in the last, with 30-40 flowers in each. 
Var. macrodon, Baker. Leaves rigidly coriaceous, oblong, about 2 
in. long, distinctly petioled, strongly 3-5-nerved, cuneate at the base, 
with many large lanceolate or deltoid rather obtuse teeth. Heads as in 
vars. balsamica and quinquenervia. 
Mauritius, common in rocky places and dry ground. The forms are connected by 
intermediate links. The first is confined to exposed places on the hills, and the two 
latter are luxuriant lowland varieties, and occur plentifully on the Platte, Flat 
Island and Gabriol Island. Var. macrodon in Rodriguez, on the south shore and 
on some of the coral islands, Balfour ! Also Bourbon. Baume Pile Platte. 
2. P. penninervia, DC. Prod. v. 319. A glutinous shrub, gla- 
brous in all its parts, with stout terete branches. Leaves crowded, 
oblanceolate, 2-3 in. long, f-f in. broad above the middle, entire, not at 
all triplinerved, narrowed from the middle into a winged petiole. Invo- 
lucre in our specimens -g- in. long; scales lanceolate, subequal, with a 
dark brown midrib and pale edges. Flowers in the form described by 
De Candolle 10-12, in our plant 30 or more. Achenes -fa in. long, half 
the length of its bristles. 
Mauritius, in mountain- woods of La Savanne and Riviere Noire. Endemic. 
* P. glutinosa , Jacq. Hort. Schoen. t. 152, of which all our specimens 
are from gardens, is evidently distinct specifically from all the varieties 
of P. trinervia. The leaves are oblong-lanceolate, acute, with regular 
teeth extending all down the edge except at the tip and cuneate base, 
and the main veins spread regularly all the way up parallel with one 
another at a broad angle from the midrib, the involucral-scales are 
fewer and more oblong than iu trinervia, the heads being in. deep and 
broad, with about 30 florets. It has always been said to be a Mauritian 
species, but if so, it seems to be now lost and the name transferred by 
the island botanists to forms of P. trinervia. 
3. P. rodriguesiana, Balf. fit. A low shrub, with terete woody 
branches rather densely clothed with adpressed white cottony hairs. 
Leaves shortly petioled, moderately firm in texture, oblong-rhomboid, 
acute, cuneate and entire in the lower third, the rest of the edge den- 
tate, thinly pubescent, especially beneath, the midrib with 5-6 ascend- 
ing ribs on each side, branching from it. Heads about 30-flowered, 
arranged in a dense corymb on a short pubescent peduncle. Involucre 
iV in. long. Achenes glabrous, -Jj in. long, rather shorter than the 
pappus. 
