Key to Trisetum

View taxon page for Trisetum

(For a list of species in Trisetum, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Lemma 

awn 

1. Bristle-like appendage or elongation, generally terminal. 2. Stiff, needle-like pappus element in Asteraceae.

0(2) mm ..... T. wolfii

1' Lemma awn 4–12 mm

2. Inflorescence generally panicle-like, ± dense to open; 

awns 

1. Bristle-like appendage or elongation, generally terminal. 2. Stiff, needle-like pappus element in Asteraceae.

generally > 7 mm; ovary hairy at tip

3. Spikelets generally to base of 

panicle 

1. In flowering plants excluding Asteraceae, Cyperaceae, Poaceae, and some other groups, a branched inflorescence in which the basal or lateral flowers (or some of them) open before the terminal or central flowers on any axis. 2. In Asteraceae, Cyperaceae, Poaceae, and some other groups, a panicle-like inflorescence is one in which at least some of the inflorescence units (e.g., heads in Asteraceae; spikelets in Cyperaceae and Poaceae), instead of individual flowers, are attached (stalked or unstalked) to branches and not directly to the main axis of the inflorescence and in which floral development may or may not proceed as in 1.

branches; lower inflorescence branches 

ascending 

Curving or angling upward from base, or about 30-60 degrees less than vertical or away from axis of attachment.

to 

erect 

Upright; vertically oriented.

; lower 

glume 

In Poaceae, each of generally two sheathing bracts that are the lowermost parts of a spikelet, subtending one or more florets.

3–5 mm ..... T. canescens

3' Spikelets only at tips of panicle branches; lower inflorescence branches generally 

spreading 

Oriented more or less perpendicularly to the axis of attachment; often, more or less horizontal.

; lower glume < 3 mm ..... T. cernuum

2' Inflorescence generally spike-like, dense; awns generally <= 7 mm; ovary glabrous at tip

4. Panicle 8–23 cm, interrupted; leaves densely soft-hairy; upper glumes 5.5–7 mm ..... T. projectum

4' Panicle 2.5–7(10) cm, not interrupted; leaves glabrous or densely soft-hairy; upper glumes 4–5 mm ..... T. spicatum

Please use this Google Form for Contact/Feedback

Citation for the whole project: Jepson Flora Project (eds.) . Jepson eFlora, https://ucjeps.berkeley.edu/eflora/ [accessed on ]

Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on .

We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.