Plants of Southern California: "Malacothamnus aboriginum", M. densiflorus, and M. fasciculatus


Table of Contents


Introduction
Voucher Distributions


Introduction

We have begun a project to analyze three Malacothamnus species in southern California: what has been called "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus. This page currently only contains the voucher distributions.

Voucher Distributions

We searched for vouchers of "Malacothamnus aboriginum", M. densiflorus, and M. fasciculatus on 19 June 2015 to analyze their geographic distribution. We only searched for San Diego County vouchers of what has been called M. aboriginum. None of the vouchers have yet been reviewed for reasonableness or consistency with dupes of the same voucher; i.e., these are the raw plots one would get from the Consortium, except we corrected one voucher that had the wrong county.

Fig. 1 shows the geographic distribution of all three species, and Fig. 2 zooms in on San Diego County.

Fig. 1. The geographic distribution of "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus in southern California from vouchers.

Fig. 2. The geographic distribution of "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus in San Diego County from vouchers.

Figs. 1 and 2 show that M. fasciculatus is mostly a coastal species, M. densiflorus is mostly an inland species, with "M. aboriginum" only a desert-edge species.

The elevation distribution of the San Diego County vouchers, plotted versus longitude, is shown in Fig. 3. See also where Keir has measured specimens as of 18 June 2015.

Fig. 3. Elevation vs. Longitude of "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus in San Diego County from vouchers.

Fig. 3 shows that M. fasciculatus is mostly a low-elevation coastal species in San Diego County, occurring from sea level to about 1100 feet elevation for most vouchers, with a scattering of vouchers to 1800 feet, with two at 2200 and 3200 feet that may be misdetermined M. densiflorus. The Jepson Manual eflora upper elevation is 600 m = 2000 feet.

M. densiflorus ranges mostly from 600 to 6000 feet elevation, with a few lower elevation vouchers in extreme southwest San Diego County.

"M. aboriginum" is a desert-edge species that ranges from 800 to 5600 feet elevation.

Figs. 4 and 5 display the geographic maps for two elevation cuts for the San Diego County specimens to see where the possibly-discrepant M. fasciculatus vouchers are from.

Fig. 4. The geographic distribution of "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus in San Diego County from vouchers with stated elevations between 1000 and 4000 feet. Two of the M. fasciculatus vouchers are found in the middle of many vouchers of M. densiflorus, and are likely misdetermined.

Fig. 5. The geographic distribution of "Malacothamnus aboriginum"; M. densiflorus, and M. fasciculatus in San Diego County from vouchers with stated elevations above 4000 feet. Left: latitude vs. longitude plot of all species above 4000 feet. Right: Consortium map of just M. densiflorus above 4000 feet.


Data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/).


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Copyright © 2015 by Keir Morse and Tom Chester
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
http://tchester.org/plants/analysis/malacothamnus/aboriginum_densiflorus_fasciculatus.html
Comments and feedback: Tom Chester
Last update: 20 June 2015