Carex Section Acrocystis in Monterey County California

These working notes may change as I learn more. I'm not a Carex expert!

In Monterey County, Carex Section Acrocystis includes C. globosa and C. zikae (syn. brevicaulis) (Matthews & Mitchell 2015). It might also include C. rossii; Poindexter (2019, Ch.2) mapped it as such, but possibily only in the sense that Poindexter also concluded that C. zikae should be subsumed as a subspecies under C. rossii. Poindexter's maps also suggest that C. brainerdii could potentially occur in the far east of the county.

Carex zikae is the new name for Carex brevicaulis Mack. (Global Carex Group 2015).
Carex zikae may soon be subsumed under Carex rossii (Poindexter's 2019 PhD dissertation).

Carex zikae is addressed in FNA and TJM as Carex brevicaulis; the name change post-dates those floras.

FNA - key, then descriptions for globosa and brevicaulis:

• http://floranorthamerica.org/Carex_sect._Acrocystis
• http://floranorthamerica.org/Carex_globosa
• http://floranorthamerica.org/Carex_brevicaulis

TJM - key, then descriptions for globosa and brevicaulis:

• https://ucjeps.berkeley.edu/eflora/eflora_keys.php?key=8902
• https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=17450
• https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=17307

Styer's 2019 "Flora of Fort Ord" says the widespread caespitose Carex of the Fort Ord chaparral is C. globosa. Styer's notes report that it was previously thought to be brevicaulis, but then this position was revised. Styer's list does not include brevicaulis (and therefore does not include zikae).

Fort Ord would be at the very southern limit for zikae. For example, Adams (1923) drew the southern limit at Santa Cruz, and the northern at Brittish Columbia. Poindexter (2019, Fig. 15D) drew it a little farther south, encompassing Monterey County, and north into BC. Fort Ord is in the center of the range for globosa, which is coastal Alta California and a little into northern inland Baja California. Matthews & Mitchell (2015) report globosa in "wooded & brushy slopes", and zikae (brevicaulis) in "rocky & sandy places near coast".

Both species have an interesting two-part inflorescence. The most obvious part with most of the spikes is at the upper end of a long stem; its bracts are considered cauline. But there's also a more inconspicuous part with one or two additional spikes at the the base of the stem. The terms 'cauline' ('non-basal') and 'basal' are interpreted in this context.

The keys distinguish globosa and carex by the vein count (nerve count) on the perigynia and pistillate flower bracts, with globosa having nerves that are more prominent and more numerous. This distinction is also what Mackenzie used in the original 1913 treatment.

One can discern other distinctions by comparing the species descriptions, particuarly within FNA, which is generally the more comprehensive reference for Poales. Globosa culms reach to 47 cm, whereas zikae culms extend to 19 cm. Globosa culm bases are more fibrous. Globosa leaf blades are usually shorter than the stems; zikae leaves exceed the stems. Proximal bracts of the main (distal) part of the inflorescence (not the basal part of inflorescence) are leaf-like in globosa, and scale-like in brevicaulis. Pistillate perigynia number 3-10 per spike in globosa and 1-6 in zikae. Staminate scales are ovate to lanceolate in globosa, and only lanceolate in zikae. Anthers can be longer in globosa than in zikae.

Example observations:

• https://www.inaturalist.org/observations/203426645 Carex globosa, as far as I've been able to discern so far.

Publicado el 22 de marzo de 2024 a las 04:25 PM por fredwatson