ï~~2010
THE MICHIGAN BOTANIST
109
basalibus serratulis capitulis phyllariis pluribus ligulisque latioribus et acheniis
majoribus pappi setis inaequalibus non clavatis differens.
Type
Holotype: U.S.A., Michigan, Crawford Co., N shore of Howe's Lake, ca. 6
km W of Grayling, Sec. 32, T27N R4W, Voss 11008, 14 August 1992, MICH;
Isotypes: BLH, MSC, TRT, UMBS; Paratypes (all from the same locality):
Somerville 1933, 1 September 1933, WUD-the earliest collection; Pringle
1365, 9 Aug 1972, HAM; Laureto 1119, 3 August 2001, WMU (Fig. 2).
Description
Perennial herb. Stems 4-7+ dm tall, erect, arising singly from a branching
caudex. Proximal to mid-stem glabrous, becoming increasingly strigillose distally. Basal leaves tapering to a long, winged frimbriate petiole. Petiole bases
marcescent (attached to old stems for more than one season). Blades ovate,
10-24 mm wide, 3-nerved (2 prominent lateral nerves arising proximally and
running alongside midnerve for some distance before diverging), surfaces
glabrous, margins ciliate, sparsely to regularly serrulate, each tooth appressed
and ending in a gland, apices acute. Proximal cauline leaves tapering to winged
petiole-like bases partially clasping stems, linear-oblanceolate, 150-180 mm
long, 10-24 mm wide, glabrous, 3-nerved, margins ciliate, entire, apices acute.
Mid-cauline to distal leaves sessile, blades linear-lanceolate, mid often obscurely
3-nerved, distal 1-nerved, 60-100 mm long, 5-10 mm wide, reduced distally.
Heads (15-) 20-60 (-100+), not secund, in corymbiform arrays. Branches and
peduncles moderately to densely strigillose, peduncles 6-12 mm long with 0-3
linear bracteoles. Involucres campanulate, 6-9 mm long. Phyllaries 18-24 in
3-4 series, unequal, linear to oblanceolate, 3-nerved, margins ciliate, apices obtuse to rounded. Ray florets 6-8, bright yellow, laminae 6.5-7.5 mm long and
1.2-2.0 mm wide. Disc florets 9-14, bright yellow, corollas 4.0-4.5 mm, lobes
1.0-1.4 mm. Achene obconic, 1.8-2.5 mm, glabrous, ribbed (ribs sometimes
dark). Pappus of bristles of varying length, the longer ones 4.0-5.5 mm, not
clavate.
Etymology
The specific epithet honors Dr. Edward G. Voss, a world-renowned botanist
from Michigan who wrote the manual on Michigan's flora-Michigan Flora
Volumes I-III (Voss 1972; Voss 1985; Voss 1996). Dr. Voss taught at the University of Michigan for decades, served on the editorial committee for the International Code of Botanical Nomenclature from 1969 to 1993, chaired the General
Committee on Botanical Nomenclature from 1999 to 2005, founded The Michigan Botanist, and was its editor from 1962 to 1976.
Ploidy Determination
Observations of root tip meristem cells at metaphase of mitosis revealed that
the chromosome number of Solidago vossii is 2n = 8x = 72. Figure 5 presents a
S. vossii root-tip cell at the metaphase stage of mitosis.
The term "ploidy" refers to the number of sets of chromosomes that an indi
