Taxonomy of the Polygonum douglasii (Polygonaceae ... - WLU

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tween ribs; papillae white, patent or reflexed,
dense, conical-elongate to cylindrical,
100–200 �m. Leaves: basal leaves often
caducous at flowering, upper leaves
abruptly reduced to scale-like bracts; ocreae
6–12 mm, scaberulous-papillose, free part
lacerate or disintegrating into fibers; blades
linear to narrowly oblong or lanceolate, 15–
70 � 2–8 mm; margins narrowly revolute,
denticulate-papillose; apex acute or mucronate;
papillae on the ocreae and leaf margins
are similar to those on the stems. Inflorescences
terminal, spike-like, open
thyrses; cymes 2–5-flowered � uniformly
spaced on stems and branches; bracts equaling
or somewhat longer than the flowers.
Flowers wide-open or semiopen; pedicels
patent in flower and reflexed in fruit, 0.5–
1 mm; perianth (3.5–)4–5 mm; tube 9–17%
of the perianth length, perianth lobes petaloid,
cucullate, naviculate only in the upper
1/4 part, overlapping, white or pink,
borders white to pink; midveins green, unbranched
or with short lateral branches;
perianth lobe cells elongated, 45–60 � 6–9
�m, with the anticlinal walls strongly sinuate;
epicuticular wax pattern of type 2,
with a dense intertwined pattern of reticulate
rodlets at the top of cells (Fig. 4F). Stamens
8, anthers pink to purple, 400–500
�m. Pollen of type B, 31–33 �m (Fig. 6H).
Achenes elliptic, 3.5–5 mm, enclosed in
perianth at maturity, smooth or tubercled
(Fig. 7E).
Distribution and ecology. Canada
(southern British Columbia) and western
United States. It grows in dry plains, meadows
(including serpentine) at elevations of
500–2000 m.
Phenology. Flowering May–August.
10. Polygonum gabrielae Costea & Tardif,
sp. nov. (Fig. 8) TYPE: UNITED
STATES. Oregon. Grant Co.: 7 mi S of
Mt. Vernon, dry, barren, gravelly, northfacing
serpentine slopes, overlooking
Laycock Creek, T14S, R30E, S26, 1370
m, 29 Jun 1953, Cronquist 7330 (HOLO-
TYPE: NY; ISOTYPES: MICH, MT, OSC,
RSA, UC, WS).
Annuum; caulis glaber, erectus, 3–10 cm
altus; folia oblanceolata vel obovata, 8–20
mm longa; inflorescentia terminalis densissima,
2–5 floribus axillaribus, pedicellis reflexis,
perianthium album, stamina 8;
achaenia 1.8–2 mm longa, elliptica, inclusa
vel paulo exserta. Differt a P. cascadense
bracteis brevioribus paucioribus et pedicellis
reflexis; difert a P. austiniae inflorescentia
densissima, spiciformi, floribus apertis,
perianthio albo, antheris longioribus.
Annual herbs. Stems 3–10 cm long, 4angled,
reddish green erect, zigzagged,
branched below the middle, � glabrous.
Leaves: basal leaves persistent at flowering,
upper leaves gradually transformed into a
few bracts; ocreae 2–5 mm, funnelform,
glabrous, free part hyaline � lacerate;
blades oblanceolate, spathulate or obovate,
8–20 � 3–4.5 mm, margins plane or very
narrowly revolute, smooth, apex acute to
mucronate. Inflorescences terminal, spiciform,
dense; cymes 2–5-flowered aggregated
and overlapping at stem and branch apices;
bracts scarce, shorter or equaling the
flowers they subtend. Flowers wide-open
(Fig. 3D); pedicels 0.5–2 mm, patent at
flowering and reflexed in fruit; perianth
2.2–2.6 mm, tube 8–15% of the perianth
length; perianth lobes petaloid, cucullate,
naviculate, parallel (Fig. 3E), pure white,
with green unbranched mid-veins (which
may be brownish on dried material); perianth
lobe cells are elongated, 55–65 � 8–
12 �m, with the anticlinal walls strongly
sinuate; epicuticular wax pattern of type 2,
with a dense pattern of intertwined rodlets
interrupted by small unsculputured spaces
at the top of cells (Fig. 5D). Stamens 8,
anthers purple, 325–380 �m. Pollen of type
B, 27.4–30.1 �m (Fig. 6G). Achenes elliptic,
1.8–2 mm, enclosed or slightly exserted
from the perianth at maturity, smooth (Fig.
7I).
Hickman (in herb.) identified collections
of P. gabrielae as ‘‘P. cascadense with
characteristics of P. douglasii.’’ Although
distinct, P. gabrielae shares some features
with P. austiniae and P. cascadense; however,
it differs by a dense terminal inflorescence
with overlapping cymes, wide-open
flowers with white perianth lobes, anthers
over 300 �m long, and pollen of type B. In
contrast, P. austiniae has an open, elongated
inflorescence with widely spaced cymes,