December 2012 Number 1 - Utah Native Plant Society

Utah Native Plant Society
7. Pods spreading, 6-8.8 times longer than wide, incurved less than 90°, the valves stiff papery, in longitudinal
section linear or narrowly oblong…………………………………A. lentiginosus var. bryantii
7. Pods ascending to erect, 4-6 times longer than wide, incurved less than 90° or nearly straight, the
valves leathery to thick leathery (subligneous), often with prominent reticulate veins, in longitudinal
section narrowly elliptic or oblong ……………………………………….A. lentiginosus var. wilsonii
5. Pods semi-bilocular to sub-unilocular, the septum to 1.5 mm wide, the body incurved to 180° (in most individuals
nearly circular), the valves in cross section oblong, obcordate, or triangular, in longitudinal section
narrowly elliptic, lanceolate, or linear.
8. Stems arising from a superficial root-crown; herbage glabrous to strigulose, rarely villosulous with hairs
to 1.0 mm long; habitat various; [=A. iodanthus] ………………………A. lentiginosus var. iodanthus
8. Stems arising from a subterranean root-crown; herbage densely villous to villosulous with hairs 0.7-1.2
mm long; habitat sandy pockets of alluvial fans and stabilized dunes; [=A. pseudiodanthus] ………..
………………………………..………………………………….. A. lentiginosus var. pseudiodanthus
1. Pod, in longitudinal section, ovoid to globose, the shape terete to didymous, bladdery inflated, the inflation dorsiventrally
and laterally, or bladdery-ventricose and the inflation greater dorsally and laterally than ventrally,
the valves papery membranous to stiffly papery (occasionally coriaceous), bilocular, the septum over 2 mm
wide and weakly fused to the
1. Astragalus lentiginosus var. maricopae
Astragalus lentiginosus var. maricopae Barneby, Leafl.
W. Bot. 4:140. 1945.
TYPE: U.S.A. ARIZONA: MARICOPA CO.: roadside
near Tempe, 4 May 1926, G.J. Harrison 1790
(HOLOTYPE: US!). Map: Figure 1.
Short lived perennial herbs, 3-8 dm tall; stems ascending,
single or several in clumps from a superficial root
crown; herbage glabrous to sparsely strigulose with basifixed
hairs; stipules 3-8 mm long, ovate-, lance- or deltoid-acuminate,
mostly recurved, partially or fully amplexicaul-decurrent,
none connate; leaves 6-16 cm long;
leaflets 15-23 (25), ovate, suborbicular, or obovate, the
apex obtuse or emarginate, 5-22 mm long; peduncles
erect, 5-14 cm long; racemes 13-30 (35) flowered, early
elongating, flowers ascending to spreading, the axis becoming
(3) 5-12 (20) cm long in fruit; calyx 7-9 mm
long, white-, black-strigulose or mixed, the campanulate
or cylindric tube 4.5-5.5 (6.5) mm long, the teeth, subulate
to lance-acuminate, 1-2.5 mm long; petals light
lemon yellow, drying ochroleucous to brownish; banner
14-16.5 mm long; keel (10) 11-13 mm long, immaculate;
wings 12-15 mm long, whitish with light lemon
yellow tip; ovary glabrous; ovules 22-26; fruiting pedicels
persistent, ascending or spreading, straight or
curved; pod persistent, ascending or spreading, straight
or incurved less than 90, in longitudinal section linear or
narrowly oblong, in cross section cordate or terete, (17)
19-23 x 3-4 mm, 5-6 (6.2)x longer than wide, sessile on
a minute boss on the receptacle or contracted at the base
into an incipient stipe to 0.5 mm long, the valves thinly
fleshy, becoming coriaceous, stramineous, semibiloculate
to nearly biloculate (but not fused to the funicular
flange), the septum 1.5-2 mm wide, the beak
unilocular; dehiscence apical, through the beak while
still attached to the raceme.
Habitat. In mixed shrub communities, in sandy,
gravely washes (sometimes among boulders) derived
from Precambrian granites and Tertiary volcanic rocks.
Distribution. In northern Maricopa County, found in
the foothills and alluvial fans in vicinity of Cave Creek,
Fish Creek, Scottsdale, and Tempe; to be expected in
the foothills and alluvial fans from Scottsdale and
Tempe east to the mountains along both sides of the
Verde River drainage, southward to its confluence with
the Salt River, and west to the alluvial fans in the vicinity
of Saguaro Lake (see Lehto 510 from 1962 below).
Phenology. Flowering from February - April; fruiting
from April - June.
Astragalus lentiginosus var. maricopae has been
largely overlooked by most botanists since it was first
described in 1945. Based on similar floral morphology,
is has been confused with A. lentiginosus var. yuccanus.
On the valley floor and alluvial fans northeast of Phoenix,
Scottsdale, and Tempe, this taxon has become very
rare (and nearly extirpated throughout its historically
known range) due to extensive suburban housing and
golf course development. The population sampled for
molecular analysis in the vicinity of Scottsdale has already
been developed, since home construction was
well underway when the samples were collected. This
variety is the most unique morphologically, and the
most endangered of all the Palantia.
Voucher specimens examined for the morphologic
analysis. USA. ARIZONA: MARICOPA CO.:
west of intersection of Westland Drive and Pima Rd,
Scottsdale, February 2005 (fl, fr), Alexander 1621
[individuals A, C, D, E] (OSC, UNLV); along Horseshoe
Dam Rd, 0.5 mi below dam, 02 March 1989 (fl),
C.L. Jones 5, (GH, NY, RSA)
Voucher specimens examined (to be included in
future morphological analyses). U.S.A. ARIZONA:
148