Plant Species of San Jacinto Mountain: Arabis = Boechera species with non-erect fruit: Appendices

This page contains two Appendices for Plant Species of San Jacinto Mountain: Arabis = Boechera species with non-erect fruit.

Appendix 1: Munz 1974 / Jepson Manual key to separate these species

The Munz 1974 / Jepson Manual key to separate these species, slightly modified to refer just to these species and to correct some lengths, is:

1. Siliques 2-4 mm wide; seed wing (0.5?)-3? mm wide; cauline leaves with a winged petiole; seeds 2.5-5 mm long, 2-4 mm wide (including wing) ...A. repanda
1'. Siliques 1.0-3.5 mm wide; seed wing less than 1 mm wide; seeds less than 2 mm long .. (7)

7. Plant hoary with a very minute pubescence. Mostly of the desert or bordering mountains.... A. pulchra1
7'. Plant greenish, not hoary ...(13)

13. Mature fruiting pedicels spreading to ascending; siliques divaricately ascending, strongly arcuate ...A. sparsiflora var. arcuata
13'. Mature fruiting pedicels diverging at right angles to strictly reflexed; siliques straight to arcuate, diverging at right angles to stem or even deflexed ... (18)

18. Seeds biseriate; cauline leaves linear; petals 8-20 mm long ...A. pulchra2
18.' Seeds uniseriate; cauline leaves wider, petals less than 12 mm long ...(19)

19. Mature fruiting pedicels descending to strictly deflexed, straight, not widely spreading; siliques mostly straight, pendulous to appressed ... A. holboellii
19'. Mature fruiting pedicels spreading at right angles to stem, straight or arched downward; siliques straight and spreading at right angles or arcuate ... (20)

21. Pedicels slender, glabrous, 10-20 mm long; outer basal leaves broadly oblanceolate, obtuse; petals 6-9 mm long ... A. perennans
21'. Pedicels stout, pubescent, 5-15 mm long; outer basal lvs narrowly oblanceolate, acute; petals 8-12 mm long ...A. sparsiflora var. californica

A silique is the mature fruit of these species. Hoary means covered with white down. Biseriate seeds are in two clearly-separate rows in each of the two ovary chambers, one on each of the flat sides of the fruit. Uniseriate seeds appear in only a single row.

Note that A. pulchra keys in two places in the above key, and that mature fruit and seeds are critical. I have been burned several times attempting to make a determination on plants without mature fruit, so I strongly recommend waiting for mature fruit before making any determination.

The Munz / Jepson Manual keys have an error in key element 1, using a silique width minimum of 3 mm even though the minimum fruit width for A. repanda is actually 2 mm in the Munz description. Also, the maximum pedicel length for A. sparsiflora is 15 mm, not the 12 mm in the Munz key.

The Jepson Manual key to separate the two varieties of A. sparsiflora found here is:

62. Pedicel hairs ± appressed; fruit pedicel spreading-recurved; stem hairs ± appressed ... var. californica
62'. Pedicel hairs spreading; fruit pedicel ascending; stem hairs spreading ... var. arcuata

Appendix 2: Translation of Voucher Letter Designation to Voucher name


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Copyright © 2008 by Tom Chester.
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Updated 7 November 2008.