Stem Hairs in the Hedeoma drummondii complex
by Bob Harms  email-here

R. Irving's 1980 (Sida 8:257-9) article describes stem vestiture for the H. drummondii complex taxa as:

H. d.
densely pubescent or puberulent above with the hairs tightly retrorsely curling, glabrate below.
H. r. r.
densely pubescence [sic], nearly canescent above with tightly retrorsely curling hairs, glabrous below.
H. r. s.
densely pubescent above with retrorsely curling hairs, puberulent below.
This page is presented to give a somewhat clearer sense of the stem hairs, but only for the spring—early fall stem growth. Winter dimorphism (beginning with shoots at the end of September) gives much denser pubescence with longer and morphologically different trichomes — these are shown on a separate page. What the images below show are:

(5-unit scales are 5 mm. Several images are clickable.)

H. drummondii

21 Sept. 2013

12 May 2013

28 April 2013
11 May 2013
11 May 2013

H. reverchonii var. serpyllifolia

23 Sept. 2013

28 April 2013

12 May 2013

H. reverchonii var. reverchonii

4 Oct. 2013
23 Sept. 2013

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