Astragalus draft key

I figured I'd share what I've been working on. This is just a draft, but should help with the Astragalus IDs. This includes only the Texas material and will likely need a couple of New Mexico species added before this is complete. Also, I have not included the key to varieties of A. mollissimus yet. Distributions are based on Turner et al. 2003 (Atlas of the Vascular Plants of Texas).

Robust white-flowered species
,1. Plants glabrous or nearly so............A. praelongus
,1. Plants hairy..........................................2
,2. Hairs on calyces appressed, not bluish; pedicels attached at the middle of flat, proximal part of calyx; leaves green; adaxial side of leaves glabrous or nearly so......A. racemosus
,2. Hairs on calyces not appressed, bluish; pedicels attached at the base of flat, proximal part of calyx; leaves silvery; adaxial side of leaves hairy......................S. nuttalliana

Prostrate perennial species
,1. Plants glabrous or nearly so.......A. lentiginosus var. higginsii
,1. Plants hairy.......................2
,2. Leaflets of apical leaves more than 2.5x longer than wide....3
,2. Leaflets of apical leaves less than 2.5x longer than wide....4
,3. Plants producing many long creeping stems; apical leaves with strongly conduplicate leaflets.......A. crassicarpus var. crassicarpus
,3. Plants appearing nearly caespitose with few very short stems; leaflets conduplicate or not....A. lotiflorus
,4. Leaflets glabrous or nearly so adaxially; stems shaggy..............A. plattensis
,4. Leaflets densely hairy, silvery; stem hairs various.................5
,5. Plants strictly and regularly strigose; hairs appressed......................A. missouriensis
,5. Hairs shaggy, if appressed, some hairs not so producing a silvery effect.....A. mollissimus

A. plattensis and A. crassicarpus are very close and should be keyed in the same couplet once I figure out the finer distinctions.

Key by fruits
,1. Fruits glabrous or nearly so..........2
,1. Fruits hairy..........................10
,2. Fruits at least 3x longer than wide..........3
,2. Fruits less than 3x longer than wide.........6
,3. Fruits trigonous, not falcate; plants erect perennials with white flowers.......................................................A. racemosa
,3. Fruits not trigonous, falcate at least proximally; plants prostrate annuals with purple to occasionally white flowers (usually due to fading)........................................4
,4. Fruits not prominently grooved abaxially, appearing somewhat flattened; banner purple, wing petals white for apical 1/2 to 2/3rds, not purple tiped; plants large, prostrate.............A. lindheimeri
,4. Fruits prominently grooved abaxially, rounded in cross-section; banner purple to lavender or nearly white, wing petals usually white with purple or lavender stripe on ventral margin extending to tip, sometimes entire tip purple or purplish; plants small, usually ascending early on and becoming prostrate later.............5
,5. Leaves truncate or emarginate.....A. nuttallianus
,5. Leaves not as above...............A. austrinus var. austrinus
,6. Fruits mottled; leaves slenderer than A. gracilis; likely absent in the area.......A. ceramicus var. filifolius (likely absent)
,6. Not as above..............................................................................7
,7. Fruit narrowing proximally nearly to a stipe; robust, white-flowered plants...........A. praelongus
,7. Not as above..........................................................................8
,8. Fruits strongly falcate, not inflated.............A. mollissimus
,8. Fruits either not falcate, or inflated............9
,9. Fruits papery, not pigmented at maturity; plants essentially glabrous.....A. lentiginosus var. higginsii
,9. Fruits not papery, often pigmented; plants strigose.......................A. crassicarpus var. crassicarpus
,10. Fruits tiny (less than 5 mm long), roughly oblong-oval, and numerous along the inflorescence, often more than 10.....A. gracilis
,10. Fruits larger (more than 5 mm long), various in shape, and fewer, sometimes numerous usually less than 10............11
,11. Plants spring ephemerals; fruits linear..........A. austrinus (var. trichocarpa or var. austrinus depending on hair density)
,11. Plants larger perennial; fruits not linear...........12
,12. Fruits narrowing proximally to a stipe............Sophora nuttaliana
,12. Fruits not narrowing proximally...................13.
,13. Immature fruits obscurred by the corolla; mature fruits usually halfway obscured by the sepals....................Oxytropis lambertii
,13. Not as above; calyces obscuring less than a quarter at maturity or absent altogether.........................14
,14. Fruit hairs not appressed............A. lotiflorus (in part; cleistogamous plants)
,14. Fruit hairs appressed................15
,15. Mature fruits less than 2x longer than wide (not including style)..........A. plattensis
,15. Mature fruits more than 2x longer than wide (not including style)..........16
,16. Fruits gradually curved abaxially; leaflets produced during flowering usually oval or eleptical, less than 3x longer than wide...............................................A. missouriensis
,16. Fruits straight for first 2/3rds then curving sharply abaxially; leaflets produced during flowering usually narrowly elliptical, more than 3x longer than wide.............A. lotiflorus

Publicado el enero 13, 2020 05:12 TARDE por nathantaylor nathantaylor

Comentarios

@aaronliston @amzapp @jotol Here's something I threw together over the weekend. I'm sure there are a lot of others I should tag, but here's a start.

Publicado por nathantaylor hace alrededor de 4 años

@sambiology you might be interested too. I will be using the information I learned here for the panhandle trip in late May if they're still out.

Publicado por nathantaylor hace alrededor de 4 años

Bookmarked. Thank you.

Publicado por amzapp hace alrededor de 4 años

Good key so far. I've saved it and printed it out for testing.

Publicado por gcwarbler hace alrededor de 4 años

Sounds good. Let me know how it goes! As a first draft, I'm sure there's plenty to clean up. Just so you know, the leaflet characteristics can be a bit difficult to use but do work if you don't get a plant that's too young or damaged (maybe around 90% or more of the plants you'll see in the field?). Despite them being less stable, the clear advantage is that you can key the species during and before flowering without fruits.

Publicado por nathantaylor hace alrededor de 4 años

Very nice to see!

Publicado por aaronliston hace alrededor de 4 años

Thanks! It will come in handy when trying to id this difficult family.

Publicado por jotol hace alrededor de 4 años

For A. lindheimeri, the wing petals that are pure white for the apical 2/3 vs. colored to apex along the lower edge for A. nuttallianus s.l. (from Shinners & Mahler) seems to work well.

Publicado por aaronliston hace alrededor de 4 años

Thanks! I forgot that I just put in some placeholder text for my own use. I have updated it now. I will hopefully go through the key with the plants I see this spring and find any other problems.

Publicado por nathantaylor hace alrededor de 4 años

Do glabrous/hairy refer to the tops of the leaves only, or does it refer to the undersides too? For example, does a glabrous topside of leaf and hairy underside = glabrous?

Publicado por amzapp hace casi 4 años

Where it says plants hairy/glabrous, that applies to the whole plant, leaves and stems.

Publicado por nathantaylor hace casi 4 años

@ellen5 In case you find yourself in an Astragalus bind in NM. (You probably have alternate species over there, though.)

Publicado por amzapp hace casi 4 años

No kidding! I am like a babe in the woods this year. This ought to help

Publicado por ellen5 hace casi 4 años

I just noticed that the numbering was automatically "corrected" to be sequential. I have stopped this by adding commas before each of the numbers. One of these days, maybe I'll find a more elegant solution, but at least it's functional again.

Publicado por nathantaylor hace casi 2 años

@nathantaylor I just found this. Thanks so much for putting this together and sharing it! I am going to try it out now :)

Publicado por matthias22 hace 11 meses

Awesome! Hope it helps! Let me know if there are areas that don't make sense or don't work particularly well. I'm certainly not beyond making mistakes.

Publicado por nathantaylor hace 11 meses

Note: I thought I'd create a list of the members of sect. Leptocarpi for reference. Not really complete nor meant to be, but helpful for comparing the local species to species from adjacent areas. Link to Barneby's key.

Astragalus austrinus var. austrinus (iNat: A. nuttallianus var. austrinus)
Astragalus austrinus var. trichocarpa (iNat: A. nuttallianus var. trichocarpa)
Astragalus pleianthus (notes here)
Astragalus macilentus (notes here)
Astragalus nuttallianus (iNat: A. nuttallianus var. nuttalianus)
Astragalus leptocarpa (if I understand this species correctly, in between A. lindheimeri and A. nuttallianus and with straight fruits)
Astragalus lindheimeri (large flowers)

There are clearly four entities belonging to that section in the region: A. lindheimeri, A. austrinus var. trichocarpa, A. austrinus var. austrinus, nuttallianus. I can't remember the differences between the varieties of A. austrinus and I wonder if A. pleianthus. Will need to investigate them at some point.

Publicado por nathantaylor hace 11 meses

Notes on Barneby's subsect. Leptocarpi key (I'll continue to add as I continue reading):

Astragalus leptocarpus, A. lindheimeri, and A. nuttallianus var. macilentus should probably key out in the same key based on similar flower size and since A. nuttallianus var. nuttallianus routinely produces straight fruits. Honestly, I question whether var. macilentus is even more closely related to nuttallianus than to A. leptocarpus or A. lindheimeri. A. nuttallianus var. pleianthus also has somewhat atypically large flowers for A. nuttallianus (7-9 mm) too, but not as large as the others. Though, this is an important detail as A. astrinus also produces glabrous fruits.
Plants with hirsutulous fruits (A. nuttallianus var. trichocarpa) occur in West Texas. In my experience, this is just normal variation of A. austrinus, but perhaps a real entity separate from A. austrinus exists in East Texas. If so, fruit pubescence isn't a good character to distinguish these two.
The dimorphism of the leaflets is often more exaggerated than suggested in the couplet of A. nuttallianus var. cedrosensis. The leaflets of the lower leaves are often triangular (often as broad as long in some) while those of upper leaves can become more linear-elliptical.

Publicado por nathantaylor hace 11 meses

Re: Nuttalianus var. macilentus. Aaron Liston has helped me to key some of these out, and I now find them to be one of the fairly well recognizable varieties. They share with lindheimeri the largely white wing petals and are in fact so similar that I confused them with lindheimeri in the beginning. However, their inflorescences usually have at least 8 flowers whereas those of lindheimeri have rarely over 6. This seems to work fairly well. There are currently five observations that have reached RG and they reflect the concept of this variety well: https://www.inaturalist.org/observations?place_id=97394&taxon_id=239526. There are other subtle differences such as the wing petals not quite as wide as in lindheimeri and the coloration often a bit more washed out. I hope this helps.

Publicado por matthias22 hace 11 meses

I appreciate the input! I'll try to apply the info sometime.

Publicado por nathantaylor hace 11 meses

Agregar un comentario

Acceder o Crear una cuenta para agregar comentarios.