Trichomes (plant hairs) of Jaltomata species (Solanaceae)
revised 28 Feb 2015 
Link to Jaltomata homepage The information on this page may be cited as a communication with professor Thomas Mione, Central Connecticut State University, Biology Department, Copernicus Hall, 1615 Stanley Street, New Britain, Connecticut 06050-4010, United States of America
Link to description of the genus Jaltomata
Illustrations on this page were done by Luis A. Serazo

In descriptions of Jaltomata species on this web site:

Finger hairs are uniseriate and unbranched (Figures 1A, B). Gland-tipped finger hairs are shown in Figure 2.

Glands are 0.07--0.1 mm long, and have a unicellular stalk and densely staining multicellular head (Figures 1C & 3; Mione & Serazo, 1999, p. 139).

Dendritic hairs are "uniseriate, many-celled and dendroid, with branches emerging at different levels” and have three or more termini.
(Roe, 1971; quoted portion of definition from Seithe, 1979, p. 308, where the term "branchlet" was used).

Forked hairs are also uniseriate and many-celled but have only two termini.

There are two kinds of gland-tipped hairs:
a) Viscous-gland-tipped (for example covering the leaves an stems of Jaltomata sinuosa).  If these are touched with a lab tissue while observing through the dissecting microscope one can see that the droplet at the terminus is viscous and not absorbed, and
b) Non-viscous gland-tipped (on the inner [adaxial] face of the corolla of several species including J. calliantha). If these are touched with a lab tissue while observing through a dissecting microscope one can see the droplet at the terminus of the hair disappears (is immediately absorbed by the tissue).

Stigma papillae are about 0.05 mm long (Figure 4).

Figure 1. These trichomes grow on plants of the genus Jaltomata. Forked and dendritic trichomes are also common but are not shown.

The following applies specifically to collection Mione & Bye 602:

A. Trichomes of the leaves, axes, and abaxial faces of the perianth are uniseriate, multicellular, unbranched, gradually taper to a point and appear to be nonliving.

B. Trichomes of the adaxial face of the corolla are living, only distal cells contain dense cytoplasm, and the terminal cell is rounded.

C. Trichomes of the abaxial face of the corolla (also found on leaves) are living and have a multicellular head borne on a unicellular stalk. The multicellular head stains densely with neutral red but the stalk cell does not absorb this stain.

gland-tipped finger hairs on Jaltomata young branch
Figure 2. Gland-tipped finger hairs on young branch of Jaltomata sanchez-vegae
(Photo by Thomas Mione, Mione et al. 647, plant grown in Connecticut, USA)
Figure 3. Many Jaltomata species have this kind of trichome on the perianth. These are living and have a multicellular head borne on a unicellular stalk. The multicellular head stains densely with neutral red but the stalk cell does not absorb this stain (Mione & Serazo, 1999; illustration by Luis A. Serazo).
Figure 4. These stigma papillae are 45 micrometers long.
(Jaltomata sanchez-vegae was grown in Connecticut, USA from seeds collected in Peru, photo by Thomas Mione, Mione et al. 647).

Figure 5.

Trichome from the corolla of J. procumbens.

 

compound microscope,

Mione 844

prepared from a living corolla

these ranged from 0.2 to 0.325 mm long and are gland-tipped

no stain

 

Photo by Gabriella Moreno & T. Mione

 

Literature Cited