146 ON SOUTH-AMERICAN APOCYNACEJE. 
rounded and shortly cordate, the summit suddenly constricted into a short acute acumen, 
margins subrevolute, chartaceous, reddish green above, opake, suleate on the midrib 
and on 10 pairs of ascending nerves, and on the transversely retieulated veins, ferru- 
ginously opake beneath, with prominent red midrib nerves and veins, scabridulous to 
the touch, 34—44 in. long, 13-23 in. broad, on patent slender petioles 8-12 lines long; 
raceme solitary and lateral, as long as the leaves, on a peduncle bare at its base, bearing 
above several flowers on slender hirtellous pedicels 3 lines long; sepals lanceolate, 
acuminate, erect, very membranaceous, glabrous, hirtellous at the base, 4 lines long, 
3 line broad, each with a broad acute inner scale; tube of corolla cylindrical, broadening 
a little upwards, 8 lines long, with a crenate annular ring in the mouth, and below it 5 
linear membranaceous appendages partly exserted ; stamens seated a little above the 
middle of the tube on hirtellous filaments; anthers acuminate, reaching the mouth, with 
2 long slender divaricating prongs at their base; disk 5-lobed, about as long as the ovary. 
5. PRESTONIA SEEMANNI, nob.: Prestonia tomentosa, Seem. (non R. Br.) in Bot. Her. p. 168. Panama, 
in uliginosis : v. s. in herb. Mus. Brit. ex loc. citat. (Seemann). 
A species distinct from P. tomentosa. Its leaves are oblong-ovate, rounded and sub- 
cordate at the base, above the middle narrowing gradually and attenuated into a sharp 
point, chartaceous, bright green above, pilose, with curving ascending prominulent 
nerves, paler beneath, densely covered with yellow tomentum, 5-33 in. long, 12-24 in. 
broad, on tomentous petioles 2 lines long; inflorescence lateral, covered with long 
sericeous hairs, with many flowers congested into a globular head, upon a shortish 
peduncle; pedicels hairy, 4 lines long; sepals 6 lines long, lanceolate-ovate, covered on 
both sides with long soft hairs, each with a long 3-denticulate scale, pilose outside; 
tube of corolla cylindrical, membranaceous, with parallel nerves, pilose outside, 6 lines 
long; segments oblong, rigidly hirsute, especially at the apex, with very long, yellow, 
rigid hairs; stamens exserted beyond the linear appendages of the throat; disk urceo- 
late, submembranaceous, 13 line high, its short marginal lobes tridenticulate, twice 
as long as the ovary. 
6. PRESTONIA CALYCINA, Müll. Z. c. p. 162. In Brasilia, prov. Minas Geraés (St.-Hilaire) : non vidi. 
This handsome species must not be confounded with Hemadictyon calycinum, Benth. 
Its branches are densely clothed with rigid retrorse ferruginous hairs, the older ones sub- 
glabrous; leaves broadly ovate-elliptic, rounded and plicate at the base, shortly acumi- 
nate, rigidly membranaceous, darkish brown above, sparsely puberulous, with villous 
margins, below rigidly tomentous, 4-42 in. long, 24—34 in. broad, on petioles 14 line 
long; axillary inflorescence capitate, on a peduncle 7 lines long, and covered with 
ferruginous hairs; bracts acuminate, sparsely pilose, 94-104 lines long; sepals acumi- 
nate, pilose, as long as the bracts, each with an internal oblong 2-3-denticulate scale; 
corolla 13 in. long ; tube a little swollen at the base; segments ovate, somewhat shorter 
than the tube, the linear appendages in the throat bilobed and papillous; stamens a 
little exserted ; disk urceolate, cleft halfway down into 5 entire lobes. 
A species said to be near Prestonia Surinamensis. 
