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BOTANICAL EXPLORATION IN VENEZUELA - I 45
width of achene, the surface whitish crustaceous-squamose, these
scales deciduous in age (Fig. 6, c).
Type in herb. Chi. Nat. Hist. Mus., collected on Paramo de los
Colorados, between El Molino and San Isidro Alto, state of Meri'da,
alt. 2745-2955 m., May 14, 1944, Julian A. Steyermark 56550.
From R. racemosa C. Wright, which it resembles, this species
differs in the subfasciculate instead of racemose inflorescences,
and paler, less rugulose achenes with smaller superficial cells.
From R. cryptantha C. B. Clarke it
may be distinguished by the less
foliose culms, different type of inflorescence, which is not concealed
among the leaves or bracts.
Rhynchospora ptaritepuiana Steyermark, sp. nov.
Perennis; culmis infra foliatis, 6-7 dm. altis; foliis erectis, supra
glabris, infra costa glabra vel breve pilosa, aliter glabris, 25-45 cm.
longis, 3-3.5 mm. lads; paniculis 2-6, brevibus, 2-4 cm. longis,
1.5-3.5 cm. latis, axillaribus terminalibusque; pedunculis tenuibus,
3.5-8.5 cm. longis; bracteis infimis foliaceis, usque ad 17 cm.
longis; spiculis fusiformi-ellipticis, 4.5-5 mm. longis, 1.5 mm. latis,
5-floris, 5-carpis; squamis ovatis breviter aristatis vel mucronatis
ferrugineis; setis 6, antrorse hispidulis, quam tuberculo aequantibus
vel longioribus, 2-2.2 mm. longis; achaenio ovoideo, basi substipitato,
superne rotundato, 1.5 mm. longo, 1 mm. lato, nitido, subtilissime
puncticulato; tuberculo late conico, basi bilobato, 1.1-1.2
mm. longo, glabro; stylo indiviso vel parce diviso.
Culms glabrous, usually taller than the leaves; spikelets with
7-9 scales, on short pedicels 1.5 mm. long; scales glabrous, the
lower short-aristate, the upper aristate or merely acute and mucronate,
ferruginous; achene abruptly narrowed to a substipitate base 0.3 mm.
long, rounded above, rufous- or dark brown, shining and appearing
smooth, but the surface superficially cellular with reticulations
broader than high; tubercle about 3/4 width of achene, loosely cellular
with depressed cells (Fig. 6, a).
Type in herb. Chi. Nat. Hist. Mus., collected on dripping sandstone
bluffs, Ptari-tepui', at base of first line of bluffs, on southfacing
part, east of "Cave Rock", state of Bolivar, alt. 2130 m.,
November 4, 1944, Julian A. Steyermark 59830. Also collected on
moist bluff, Ptari-tepui, at base of and on main south-facing high
sandstone bluffs, alt. 2400-2410 m., October 30, 1944, Steyermark
59599.
A member of Series Haplostyleae, Div. Calyptrostylis, Sect.
Paniculatae (following Clarke's subdivisions), this species is apparently
related to R. polyphylla Vahl, from which it differs in the
more elongated, erect, narrower leaves, which are more crowded
towards the base of the culm and not so uniformly scattered along the
length of the culm, in the shorter inflorescences of brown spikelets,