214 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
Stamens hypogynous. 
Leaves glabrate. 
Spike not longer than leaf. 
P. Diguetianum. 
Spike distinctly longer. 
Leaves puberulent; spike elongated. 
P. Mas. 
P. Rosei. 
Stamens adnate to ovary: leaves pubescent. 
Style very prominent. 
Style nearly suppressed. 
P. ahalienatum. 
P. albicaule. 
Piper ovatum Vahl, Eclog. 3. PI. i. 1796. — CDC, Prod. i6^- 253, and 
Urban, Symbolae Antillanae 3: 174. 
Glabrous; leaves ovate-elliptic, acuminate, narrowed and nearly equally 
cordulate at base, moderately small (5-6.5 X 12-14 cm.), pinnately nerved 
throughout, the nerves 10 or 12 X 2; petiole short (10 mm.); spikes moder- 
ately short (50 mm.); peduncle equaling the petiole; bracts concave; 
flowers short-pediceled, perfect, hypog3mous, 4-androus; ovary with a short 
style; stigmas 4; berries ovoid-attenuate. 
Trinidad, West Indies {Ryan, the type; Purdie; Fendler 66g; not known 
to be represented in North American herbaria). 
Pi^erikf^g/Zm CDC, Prod. 16^:243. 1869. 
More or less soft-pubescent; leaves elliptic-ovate, acuminate, rounded 
at base, small (scarcely 5 X 12 cm.), palmately 5- or 7-nerved, bullate in 
age; petiole short (5-10 mm.); spikes moderately short (50 mm.); peduncle 
exceeding the petiole (15 mm.); bracts concave; flowers pedicellate with 
the pedicels unequally long up to 1.5 mm., perfect, 6-androus, with hypogy- 
nous anthers rather shorter than the filaments; stigmas 3, sessile; berries 
round-ovoid, apiculate. — Plate V, figure i. 
Eastern Sierra Madre, Mexico, about Orizaba {Mueller 180, the type; 
Botteri 11 56). 
Piper yucatanense CDC, Linnaea 37: 334. "1871-3." 
Closely resembling P. Muelleri but glabrous throughout, the subsessile 
leaves ovate and measuring 6.5 X 12 cm. 
Yucatan, Mexico {Linden 184: not known to be represented in American 
herbaria.) 
Piper Neesianum CDC, Prod. 16^: 256. 1869. 
Glabrous except that the leaves are minutely puberulous beneath; 
leaves lance-elliptic, long-acuminate, acute and minutely unguiculate- 
auriculate at base, small (scarcely 4 X 10 cm.), palmately 5-nerved; petiole 
moderate (10 mm.); spikes very short (scarcely 20 mm.); peduncle half as 
long as the spike; bracts evanescent; flowers pedicellate with the pedicels 
scarcely over i mm. long, 3- to 6-androus, hypogynous; ovary ovoid or 
oblong-ovoid; stigmas 3, sessile. — Plate VII, figure i. 
Eastern Sierra Madre, Mexico (without indicated locality, Karwinski 
82 J, the type); Papantla {Liehmann 18) \ Orizaba {Botteri 192). Also 
reported from Nicaragua {Tate 36'/). 
Piper Thiemeanum n. sp. 
Glabrous; leaves ovate-lanceolate, long-acuminate, rounded at base, 
