Sporobolus pyramidatus
Sporobolus interruptus
Madagascar dropseed, whorled dropseed
black dropseed
7-35(60) cm, erect or decumbent.
25-60 cm.
rounded below, margins and apices hairy, hairs to 3 mm;
ligules 0.3-1 mm;
blades 2-12(20) cm long, 2-6 mm wide, flat, abaxial surface glabrous, adaxial surface scabridulous, sometimes sparsely hispid, margins ciliate-pectinate.
dull and fibrous basally, with scattered, contorted hairs to 5 mm, margins glabrous;
ligules 0.2-0.7 mm;
blades (5)8-20 cm long, 1-2.5 mm wide, flat to folded, glabrous or scattered-pilose on both surfaces, margins glabrous.
4-15(18) cm long, 0.3-6 cm wide, open (contracted when immature), pyramidal;
lower nodes with 7-12(15) branches;
primary branches 0.5-4.5 cm, spreading 30-90° from the rachis, with elongated glands, without spikelets on the lower 1/3 – 1/2, secondary branches appressed;
pedicels 0.1-0.5 mm, appressed.
5-20 cm long, (0.6)1-8 cm wide, longer than wide, narrowly pyramidal, open to somewhat contracted, not diffuse, well-exerted from the upper leaf sheath;
lower nodes with 1-2(3) branches;
primary branches 0.6-7 cm, appressed or spreading to 70° from the rachis, not capillary, without spikelets on the lower 1/3;
pedicels 0.8-5.5 mm, appressed to spreading.
1.2-1.8 mm, plumbeous or brownish, often secund along the branch.
4.5-6.6 mm, plumbeous.
unequal, ovate to obovate, membranous;
lower glumes 0.3-0.7 mm, without midveins;
upper glumes 1.2-1.8 mm, at least 2/3 as long as the florets, often longer;
lemmas 1.2-1.7 mm, ovate to elliptic, membranous, glabrous, acute;
paleas 1.1-1.6 mm, ovate to elliptic, membranous, glabrous;
anthers 0.2-0.4 mm, yellowish or purplish.
unequal, lanceolate, membranous;
lower glumes (2)2.5-4.2 mm;
upper glumes 3.8-6.5 mm, at least 2/3 as long as the florets;
lemmas 5-6.5 mm, ovate, membranous, glabrous, acute;
paleas 4.8-6.5 mm, ovate, membranous;
anthers 3-4.2 mm, yellow to purplish.
0.6-1 mm, obovoid, faintly striate, light brownish.
about 3 mm long, 1.5-1.7 mm thick, pyriform-globose;
embryo dark brown to blackish;
endosperm reddish-brown.
= 24, 36, 54.
= 30.
Sporobolus pyramidatus
Sporobolus interruptus
Sporobolus pyramidatus is native to the Americas, extending from the southern United States to Argentina. It grows in disturbed soils, roadsides, railways, coastal sands, and alluvial slopes in many plant communities, at elevations from 0-1500 m. Morphologically, it is very similar to the Eastern Hemisphere S. coromandelianus (Retz.) Kunth, suggesting that they are closely related.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Sporobolus interruptus grows on rocky slopes and in dry meadows of open yellow pine and oak-pine forests and pinyon-juniper woodlands, at elevations from 1500—2300 m. It is an Arizonan endemic that is morphologically similar to S. heterolepis, but the two species are separated geographically, the range of the latter lying to the north and east of Arizona. The only reliable morphological difference between them is anther length (3-4.2 mm long in S. interruptus, 1.7-3 mm long in S. heterolepis). Cytologically, S. interruptus appears to be triploid, while 5. heterolepis appears to be an octoploid (2n = 72).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
LA Plants
MD Biodiversity
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
