Sporobolus Lemma Micromorphology

Sporobolus Lemma Micromorphology

by Bob Harms email-here

SEM scans of the lemma abaxial surface for the Sporobolus compositus and S. vaginiflorus complexes supports the species distinctions of recent treatments. The following 6 characters were found: bicellular microhairs, hooks (found only with S. vaginiflorus), long cells, macrohairs, prickles, silica cells. Images shown below.

[Click image to enlarge]

Prickle	Silica Cell
S. clandestinus [16,060X]	S. clandestinus [12,670X]	S. compositus var. compositus [13,210X]	S. neglectus [10,840X]

Bicellular Microhair			Hook	Macrohair
S. neglectus [49,370X]	S. neglectus [10,840X]	S. vaginiflorus [3,170X]	S. vaginiflorus [13,350X]	S. vaginiflorus [3,170X]

Long cells with strongly sinuate sides cover the entire lemma surface for all taxa, although these are not clearly visible when densely covered with hooks. Unicellular macrohairs, visible with a hand lens, were present and visible on several scans. A count of other lemma micromophological characters on the lemma body away from the midrib is shown in the following table:

Density of characters in a 100 μm² intercostal area (calculated from areas of varying size).

^Prickles were found with all taxa in the vicinity of the midrib or near the tip,
but never with the density found with S. clandestinus*.

For Lemma Surface Scans

Plant Resources Center Home Page — Flora of Texas — Sporobolus

Density of characters in a 100 μm2 intercostal area (calculated from areas of varying size). *Prickles were found with all taxa in the vicinity of the midrib or near the tip, but never with the density found with S. clandestinus.

For Lemma Surface Scans

Density of characters in a 100 μm² intercostal area (calculated from areas of varying size).

^Prickles were found with all taxa in the vicinity of the midrib or near the tip,
but never with the density found with S. clandestinus*.