December 2012 Number 1 - Utah Native Plant Society

Calochortiana December 2012 Number 1
ilar morphologically than A. lentiginosus var. maricopae
is to A. lentiginosus var. wilsonii. The morphological
similarity and geographic proximity of A. lentiginosus
var. mokiacensis and A. lentiginosus var. ursinus (the
nearest populations are at least 20 km apart in adjacent
mountain ranges) has been the primary evidence for
placing them into the same taxon in the latest monograph
(Welsh 2007). The morphological distinctiveness
of A. lentiginosus var. ursinus is subtle, but it is, nevertheless,
present. In the A. lentiginosus var. mokiacensis
PCoA analysis, specimens of A. lentiginosus var. ursinus
appear to grade into the specimens of A. lentiginosus
var. mokiacensis (including the type specimens of A.
lentiginosus var. trumbullensis). The parsimony and
cluster analyses also show A. lentiginosus var. ursinus
in the same region of the tree as A. lentiginosus var.
mokiacensis. However, A. lentiginosus var. ursinus does
not share haplotypes with A. lentiginosus var. mokiacensis.
It shares the most haplotypes with A. lentiginosus
var. wilsonii (Alexander & Liston, in prep). Based on
the lack of shared haplotypes with A. lentiginosus var.
mokiacensis and a trend toward smaller pods and flowers
(see the taxonomic treatment below for more specific
morphological differences), A. lentiginosus var.
ursinus is recognized herein at the varietal level following
the delimitation proposed by Barneby (1945, 1964).
Taxonomic Treatment
The taxonomic revision herein is a first step in a full
monograph of the Astragalus lentiginosus complex. As
such, the specimens used in the morphological analysis
are labeled in a separate voucher list. Where applicable,
a list of specimens examined by the author but not yet
included in morphological analyses is also included.
Species delimitations in the taxonomic revision follow a
phenetic species concept (Sokal, 1973; Luckow 1995).
The original goal of this study was to apply a phylogenetic
species concept, however, the genetic and morphologic
data obtained could not be analyzed robustly
using cladistic methodologies. Primarily, population
level data are largely ignored since the smallest taxonomic
units of phylogenetic analyses are species (Nixon
& Wheeler 1990, Cracraft 1983, Luckow 1995). Table 1
is a list of notable specimens identified in maps in this
revision. Following the key are complete taxonomic
treatments for A. lentiginosus var. maricopae and A.
lentiginosus var. ursinus. Treatments for the other taxa
in the key can be found in Alexander (2008).
Key to the Palantia and related varieties of Astragalus lentiginosus
1. Pod, in longitudinal section, linear, lanceolate, oblong, or elliptic, the shape cylindrical and not inflated or ventricose
and scarcely inflated dorsally or laterally, the valves stiffly papery to coriaceous, bilocular, semibilocular,
or sub-unilocular, the septum to 2.5 mm wide and not fused to the funicular flange.
2. Pods long-persistent, sessile on a minute boss on the receptacle or contracted at the base into an incipient stipe
0.4 to 0.7 (1.0) mm long.
3. Banner light yellow, without a central white or striped spot (immaculate); keel slightly darker than the banner,
drying yellowish brown and immaculate; wings slightly darker than the banner, drying yellowish brown.
…………………………………………………………………………………..A. lentiginosus var. maricopae
3. Banner light to dark purple with a white & purple striate central spot; keel light purple & dark purple maculate;
wings light to dark purple, sometimes with white tips.
4. Pods straight or slightly incurved, 20-28 (-32) mm long, 4-7.1x longer than wide, the pedicel ascending or
spreading, straight or curved; leaflets glabrous to moderately pubescent adaxially, at least sparsely
pubescent abaxially; [=A. mokiacensis, A. lentiginosus var. trumbullensis]………………………………
………………………………………………………………………………….A. lentiginosus var. mokiacensis
4. Pods incurved, 13-20 (-23) mm long, 2.4-4.7x longer than wide; the pedicel ascending or erect, straight
or curved; leaflets glabrous adaxially, glabrous or sparsely pubescent abaxially; [=A. ursinus] ……….
………………………………………………………………………………………A. lentiginosus var. ursinus
2. Pods deciduous (sometimes tardily so) by a cellular abscission layer between the receptacle and gynoecium,
sessile on a minute boss on the receptacle or contracted at the base into an incipient stipe or gynophore 0.3 to
0.5 (0.7) mm long.
5. Pods semi-bilocular to nearly bilocular, the septum 1-2.5 mm wide, the body incurved 120-180°, incurved
less than 90°, or straight, the valves in cross section cordate, obcordate, or terete, in longitudinal section
elliptic, linear, or oblong.
6. Pods falcate to hamate (nearly circular), occasionally lunate, incurved to 120-180°, the pedicel deflexed
or declined…………………………………………………………………. A. lentiginosus var. palans
6. Pods lunate to falcate, incurved less than 90° to nearly straight, the pedicel erect, ascending, or spreading.
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