| John R. Reeder |
Plants perennial; cespitose, essentially
glabrous throughout. Culms 30-130 cm. Sheaths open; ligules
of hairs; micro hairsof blades with an inflated terminal cell similar in
length to the basal cell. Inflorescences terminal, narrow, spikelike or
somewhat open panicles; disarticulation above the glumes but not between
the florets, these falling together. Spikelets with 3-5 florets, only the
lower 1-3 bisexual. Glumes subequal, thin, membranous, 1-veined, acute;
lemmas rounded on the back, hairy at least basally, obscurely (5)7(9)-veined,
veins extending into scabridulous awns of unequal length, several additional narrow
awnlike lobes usually also present, awns and lobes together forming a pappuslike
crown; paleas textured like the lemmas, 2-veined, 2-keeled, keels scabrous
or hairy; anthers 3; styles 2. Caryopses elliptical, plump,
slightly dorsally flattened or nearly terete; embryos about 1/2 as long
as the caryopses. x = 10. From the Greek pappos, pappus, and phoros,
bearing, in reference to the pappuslike crown of the lemma.
Pappophorum is an American genus with about eight species. It grows in
warm regions of North and South America. There are two species native to the Flora
region.
1 |
Panicles
purple-tinged, narrow, but usually with some slightly spreading branches;
lemma bodies 3-4 mm, the awns mostly not more than 1.5 times as long,
these rarely spreading at right angles ..... 1. P.
bicolor |
Panicles white or tawny, rarely slightly
purplish, tightly contracted; lemma bodies 3-3.2 mm, the awns about twice
as long, commonly spreading at right angles when mature ..... 2.
P. vaginatum |
1. Pappophorum bicolor E. Fourn.
Pink Pappusgrass
Culms 30-80(100) cm. Sheaths mostly glabrous, apices with a tuft
of hairs on either side; ligules about 1 mm; blades 10-20(30) cm
long, 2-5 mm wide, flat to involute. Panicles 12-20 cm, narrow but usually
with some slightly spreading branches, pink- or purple-tinged. Spikelets
with the lower 2 or 3 florets bisexual, distal 1-2 florets sterile. Glumes
3-4 mm, thin, glabrous, apices acute or minutely notched and mucronate; lemmas
somewhat firm, usually faintly 7-veined, with 11-15 awns; lowest lemma bodies
3-4 mm, midveins and margins pubescent from the base to about midlength, awns
about 1.5 times as long as the lemma bodies; paleas subequal to the lemma
bodies or slightly longer. Caryopses about 2 mm. 2n = 100.
Pappophorum bicolor grows in open valleys, road right of ways, and grassy
plains in Texas and northern Mexico. A report for Arizona (Mearns 1175)
was apparently due to mixed labels. There have been no subsequent reports of the
species from the state.
2. Pappophorum vaginatum Buckley
Whiplash Pappusgrass
Culms (40)50-100 cm. Sheaths mostly glabrous, with a tuft of hairs
at the throat; blades 10-25 cm long, 2-5 mm wide, flat to involute, adaxial
surfaces scabridulous. Panicles 10-25 cm, tightly contracted, usually white
or tawny, rarely slightly purple-tinged. Spikelets with 1(2) bisexual florets
and 2 reduced florets. Glumes (3)4-4.5 mm, glabrous, acute; lowest lemma
bodies 3-3.2 mm, midveins and margins pubescent from the base to about midlength,
awns about twice as long as the lemma bodies, tending to spread at right angles
when mature; paleas longer than the lemma bodies. 2n = 60.
Pappophorum vaginatum grows in similar habitats to P.
bicolor, the two species sometimes growing together. Its range extends
from southern Arizona to Texas and northern Mexico and from Uruguay to Argentina.