Laphamia cochisensis Niles

  • Authority

    Niles, Wesley E. 1970. Taxonomic investigations in the genera Perityle and Laphamia (Compositae). Mem. New York Bot. Gard. 21: 1-82.

  • Family

    Asteraceae

  • Scientific Name

    Laphamia cochisensis Niles

  • Description

    Latin Diagnosis - Caules ex erectis ad patentes, graciles, striati, ad ca. 1 dm altos, simplices ramosive, puberli, minute glandulosi, vetustate purpurascentes. Folia opposita alternave; laminis ex ovatis ad deltoideo-ovatas ambitu, apice acuto, vulgo tripartitis; lobo medio longissimo, acuto, asepe uno plurimisve dentibus divergentibus acutisque instructo; lobis lateralibus plerumque late patentibus prope basim, acutis, integris vel saepe saltem uno dente divergente acuto que instructis; basi e truncata ad acuminatam saepe obliqua, ad 2 cm longa atque 1.5 cm lata; superficiebus glabris vel ad marginem puberulis, minute glandulosipunctatis; petiolis elongatis, ad 2.5 cm longis vulgo quam lamina longioribus, anguste alatis, leviter ad basim dilatatis, puberulis atque minute glandulosipunctatis. Involucri plerumque solitarii atque terminales, pedunculis puberulis glandulosisque minus quam 1 cm longis, late campanulati, foliis superis recondita vel ea superantes; phyllaria ca. 14—18, in duobus seriebus fere aequalibus, ad 7 mm long atque 2 mm lata, e lanceolatis ad anguste ovata, apicibus complanatis tomentosis, ad marginibus superis puberula et breviciliata, dorsaliter carinata, vetustate patentia. Flores radiales carentes. Disci flores multi (ca. 60), lutei, glandulosi, quadrilobati, tubo fauceque distinctis, fauce 2 mm long quam tubo duplo longiori. Pappus praesens carensve, praesens plerumque una arista minute barbellata ad 2.5 mm longa vel rariter cum altera multo breviori ad marginem oppositam achenii. Achenia plerumque ex anguste ellipticis ad anguste obovata vel transversaliter anguste elliptica vel leviter quadrangula, ad 3.5 mm long atque 1 mm lata, puberula, maturitate nigra, nervo marginali.

    Species Description - Stems upright to spreading, slender and striate, to about 1 d m tall, simple or branched, puberulent, minutely glandular, becoming purplish in age. Leaves opposite or alternate; blades ovate to deltoid ovate in outline, apex acute, commonly tripartite, the middle lobe the longest, acute and often bearing one or a few divergent and acute teeth, the lateral lobes usually widely divergent from near the base, acute, entire or often each with at least one divergent and acute tooth, base truncate to acuminate and often oblique, to 2 cm long and 1.5 cm broad, surfaces glabrous or puberulous along the margin, minutely glandular punctate; petioles elongate, to 2.5 cm long and generally exceeding the blade in length, narrowly winged and somewhat expanded at base, puberulent and minutely glandular punctate. Involucres mostly solitary and terminal, on puberulous and glandular peduncles less than 1 cm long, broadly campanulate, concealed by or barely exceeding the upper leaves; phyllaries about 14-18, in two nearly equal series, to 7 mm long and 2 mm broad, lanceolate to narrowly ovate, the tips flattened and tomentose, puberulous and shortly ciliate on the upper margins, carinate on the back, spreading in age. R a y florets absent. Disc florets numerous (ca. 60), corollas glandular, yellow, with distinct tube and throat, the throat 2 mm long and about twice the length of the tube. Pappus present or absent, if present then usually of a single and minutely barbellate awn to 2.5 mm long, or occasionally with a second and much shorter awn arising from the opposite margin of the achene. Achenes mostly narrowly elliptic to narrowly obovate, transversely narrowly elliptic or faintly quadrangular, to 3.5 mm long and 1 mm broad, puberulous, black at maturity, with a marginal nerve. Chromosome number: n = 17.

  • Discussion

    Laphamia cochisensis is another of the narrow endemics which is found in the genus. Its leaves are typically three-lobed, and in this feature they most closely resemble those displayed by L. gracilis and L. gilensis, which occur farther north in Arizona and in Nevada, and by L. staurophylla of southern New Mexico. L. cochisensis is effectively separated from L. gracilis by having petioles which are longer than the leaf blade; and by a greater number of disc florets per head. The absence of ray florets distinguishes the species from L. gilensis and L. staurophylla.

    Type. North-facing cliffs of Echo Canyon, elev ca. 2,000 m , Chiricahua National Monument, Chiricahua Mts., Cochise County, Arizona, Niles 377, 10-V-1964 (Holotype: ARIZ).

  • Distribution

    Distribution (Fig. 31). Arizona, Cochise County; known only from rock ledges and cliffs of canyons in the Chiricahua National Monument; September and October. ARIZONA. Cochise County: "vertical ledges, Bonita Canyon, Chiricahua National Monument, Clark 8611 (UNM); on bedrock of north slopes along Sugarloaf Mountain trail, near west end of tunnel, elev ca. 2,100 m, Chiricahua National Monument, Chiricahua Mts., Niles 450 (ARIZ).

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